Updated on 2025/04/20

写真a

 
ZHANG, Xichao
 
News & Topics
Affiliation
Faculty of Science and Engineering, Waseda Research Institute for Science and Engineering
Job title
Junior Researcher(Assistant Professor)
Degree
Doctor of Philosophy ( 2018.09 Shinshu University )
Mail Address
メールアドレス
Homepage URL
https://w-rdb.waseda.jp/html/100003521_en.html
Profile

Dr. Xichao Zhang is an Assistant Professor at Waseda University. He is a member of Prof. Masahito Mochizuki’s Theoretical Group. He received his Ph.D. from Shinshu University in 2018, and worked as a JSPS Postdoctoral Fellow at Shinshu University (2020-2022). He also worked at the Chinese University of Hong Kong, Shenzhen (2016-2020) and the University of Hong Kong (2014-2016).

Dr. Zhang’s research interests encompass magnetism, spintronics, and nanoscience, with a focus on the theoretical and computational study of spin textures, spin dynamics, and spintronic devices. He has spent more than ten years exploring different species of topological spin textures, including skyrmions, skyrmioniums, bimerons, and bimeroniums. Some specific systems that Dr. Zhang works on include bulk chiral magnets, thin films with interfacial chiral interactions, synthetic antiferromagnetic and ferrimagnetic multilayers, and low-dimensional frustrated spin systems. He has also been investigating functional applications for several years, such as logic computing gates that utilize spin textures as information carriers. Recently, Dr. Zhang’s research particularly focuses on the complex dynamics of particle-like spin textures interacting with artificially nanostructured surfaces and interfaces. In addition, he works on interdisciplinary topics that bridge magnetism and spintronics with biological physics, soft matter, and fluid science. Examples include the flow phenomena of particle-like spin textures and the active matter behaviors in magnetic systems.

Dr. Zhang has published more than 40 first and co-first author papers in peer-reviewed academic journals, including Nature Physics, Nature Electronics, Nature Communications, Physical Review Letters, Nano Letters, and Applied Physics Letters. He has also coauthored over 80 peer-reviewed academic papers through international collaborations with leading universities and industry organizations. Besides, he has contributed five invited chapters to three academic books published by Taylor & Francis Group, Elsevier, and Springer. Dr. Zhang’s research contributions have earned him widespread recognition in the scientific community. His Google Scholar citations are over 11,000 with an h-index of 46. He has been ranked among the World’s Top 2% Scientists by Stanford University since 2020. In 2024, Dr. Zhang was elected as an IEEE Senior Member. In 2025, Dr. Zhang received the prestigious Waseda Research Award (High-Impact Publication Category, AY2024).

>>>SELECTED PUBLICATIONS<<<

[01] “Skyrmion Dynamics in a Frustrated Ferromagnetic Film and Current-Induced Helicity Locking-Unlocking Transition”,
X. Zhang, J. Xia, Y. Zhou, X. Liu, H. Zhang, and M. Ezawa,
Nature Communications 8, 1717 (2017).
DOI: 10.1038/s41467-017-01785-w

[02] “Magnetic Bilayer-Skyrmions without Skyrmion Hall Effect”,
X. Zhang, Y. Zhou, and M. Ezawa,
Nature Communications 7, 10293 (2016).
DOI: 10.1038/ncomms10293

[03] “Configurable Pixelated Skyrmions on Nanoscale Magnetic Grids”,
X. Zhang, J. Xia, K. Shirai, H. Fujiwara, O. A. Tretiakov, M. Ezawa, Y. Zhou, and X. Liu,
Communications Physics 4, 255 (2021).
DOI: 10.1038/s42005-021-00761-7

[04] “Magnetic Skyrmion Logic Gates: Conversion, Duplication and Merging of Skyrmions”,
X. Zhang, M. Ezawa, and Y. Zhou,
Scientific Reports 5, 9400 (2015).
DOI: 10.1038/srep09400

[05] “Laminar and Transiently Disordered Dynamics of Magnetic-Skyrmion Pipe Flow”,
X. Zhang, J. Xia, O. A. Tretiakov, M. Ezawa, G. Zhao, Y. Zhou, X. Liu, and M. Mochizuki,
Physical Review B 108, 144428 (2023).
DOI: 10.1103/PhysRevB.108.144428

[06] “Static and Dynamic Properties of Bimerons in a Frustrated Ferromagnetic Monolayer”,
X. Zhang, J. Xia, L. Shen, M. Ezawa, O. A. Tretiakov, G. Zhao, X. Liu, and Y. Zhou,
Physical Review B 101, 144435 (2020).
DOI: 10.1103/PhysRevB.101.144435

[07] “Control and Manipulation of a Magnetic Skyrmionium in Nanostructures”,
X. Zhang, J. Xia, Y. Zhou, D. Wang, X. Liu, W. Zhao, and M. Ezawa,
Physical Review B 94, 094420 (2016).
DOI: 10.1103/PhysRevB.94.094420

[08] “Chiral Skyrmions Interacting with Chiral Flowers”,
X. Zhang, J. Xia, O. A. Tretiakov, M. Ezawa, G. Zhao, Y. Zhou, X. Liu, and M. Mochizuki,
Nano Letters 23, 11793 (2023).
DOI: 10.1021/acs.nanolett.3c03792

[09] “A Frustrated Bimeronium: Static Structure and Dynamics”,
X. Zhang, J. Xia, M. Ezawa, O. A. Tretiakov, H. T. Diep, G. Zhao, X. Liu, and Y. Zhou,
Applied Physics Letters 118, 052411 (2021).
DOI: 10.1063/5.0034396

[10] “Direct Observation of the Skyrmion Hall Effect”,
W. Jiang, X. Zhang, G. Yu, W. Zhang, X. Wang, M. B. Jungfleisch, J. E. Pearson, X. Cheng, O. Heinonen, K. L. Wang, Y. Zhou, A. Hoffmann, and S. G. E. te Velthuis,
Nature Physics 13, 162 (2017).
DOI: 10.1038/nphys3883

Research Experience

  • 2023.01
    -
    Now

    Waseda University   Research Institute for Science and Engineering   Junior Researcher (Assistant Professor)

  • 2020.11
    -
    2022.11

    Shinshu University   Faculty of Engineering   JSPS PD

  • 2020.01
    -
    2020.11

    The Chinese University of Hong Kong, Shenzhen   School of Science and Engineering   Research Associate

  • 2019.01
    -
    2019.12

    The Chinese University of Hong Kong, Shenzhen   School of Science and Engineering   Presidential Postdoctoral Fellow

  • 2016.09
    -
    2018.12

    The Chinese University of Hong Kong, Shenzhen   School of Science and Engineering   Research Assistant

  • 2016.04
    -
    2018.09

    Shinshu University   Faculty of Engineering   JSPS RONPAKU Fellow

  • 2014.08
    -
    2016.08

    The University of Hong Kong   Department of Physics   Research Assistant

▼display all

Education Background

  • 　
    -
    2018.09

    Shinshu University   Interdisciplinary Graduate School of Science and Technology   Ph.D.  

  • 　
    -
    2014.06

    Sichuan Normal University   Department of Physics, College of Physics and Electronic Engineering   B.Sc. (Physics)  

Research Areas

  • Magnetism, superconductivity and strongly correlated systems / Applied condensed matter physics / Electric and electronic materials

Research Interests

  • Magnetism

  • Magnetic Materials

  • Nanomagnetism

  • Micromagnetics

  • Frustrated Magnetism

  • Topological Magnetism

  • Spintronics

  • Spin Devices

  • Skyrmions

▼display all

Awards

Media Coverage

▼display all

 

Papers

  • Active-matter behaviors of magnetic skyrmions

    Masahito Mochizuki, Xichao Zhang, Xiaoxi Liu

      79 ( 10 ) 549 - 554  2024.10  [Domestic journal]

    DOI

  • Confined antiskyrmion motion driven by electric current excitations

    Yao Guang, Xichao Zhang, Yizhou Liu, Licong Peng, Fehmi Sami Yasin, Kosuke Karube, Daisuke Nakamura, Naoto Nagaosa, Yasujiro Taguchi, Masahito Mochizuki, Yoshinori Tokura, Xiuzhen Yu

    Nature Communications   15 ( 1 ) 7701  2024.09  [Refereed]  [International journal]

    Authorship：Lead author

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Transformation of a cellular skyrmion to polyomino-like structures

    Jing Xia, Xichao Zhang, Yan Zhou, Xiaoxi Liu, Guoping Zhao, Masahito Mochizuki

    Applied Physics Letters   125 ( 3 ) 032404  2024.07  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    Topological spin structures with transformable shapes may have potential implications for data storage and computation. Here, we demonstrate that a square cellular skyrmion on an artificial grid pinning pattern can be manipulated by programmed current pulses. We find that parallel short pulses could result in elongation of the skyrmion mainly in the current direction, while parallel long pulses are able to induce elongation in the direction perpendicular to the current due to the intrinsic skyrmion Hall effect. Consequently, a programmed sequence of parallel pulses could lead to transformation of the skyrmion to I-, L-, and Z-shaped polyomino-like structures without affecting the topological charge. In addition, we find that orthogonal pulses could lead to the transformation to more complex polyomino-like structures, including T-shaped and irregular ones. Particularly, when a small T-shaped structure is formed, the topological charge of the system is found to be non-integer due to incomplete compensation of local topological charge densities; however, the T-shaped structure is stable on the attractive pinning pattern. Our results offer an effective way to create polyomino-like spin structures toward functional applications.

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Bimerons create bimerons: Proliferation and aggregation induced by currents and magnetic fields

    Xichao Zhang, Yan Zhou, Xiuzhen Yu, Masahito Mochizuki

    Aggregate    2024.05  [Refereed]  [Invited]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    The aggregation of topological spin textures at nano and micro scales has practical applications in spintronic technologies. Here, the authors report the in‐plane current‐induced proliferation and aggregation of bimerons in a bulk chiral magnet. It is found that the spin‐transfer torques can induce the proliferation and aggregation of bimerons only in the presence of an appropriate out‐of‐plane magnetic field. It is also found that a relatively small damping and a relatively large non‐adiabatic spin‐transfer torque could lead to more pronounced bimeron proliferation and aggregation. Particularly, the current density should be larger than a certain threshold in order to trigger the proliferation; namely, the bimerons may only be driven into translational motion under weak current injection. Besides, the authors find that the aggregate bimerons could relax into a deformed honeycomb bimeron lattice with a few lattice structure defects after the current injection. The results are promising for the development of bio‐inspired spintronic devices that use a large number of aggregate bimerons. The findings also provide a platform for studying aggregation‐induced effects in spintronic systems, such as the aggregation‐induced lattice phase transitions.

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • Magnon-Skyrmion Hybrid Quantum Systems: Tailoring Interactions via Magnons

    Xue-Feng Pan, Peng-Bo Li, Xin-Lei Hei, Xichao Zhang, Masahito Mochizuki, Fu-Li Li, Franco Nori

    Physical Review Letters   132 ( 19 ) 193601  2024.05  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Spontaneous Vortex‐Antivortex Pairs and Their Topological Transitions in a Chiral‐Lattice Magnet

    Xiuzhen Yu, Naoya Kanazawa, Xichao Zhang, Yoshio Takahashi, Konstantin V. Iakoubovskii, Kiyomi Nakajima, Toshiaki Tanigaki, Masahito Mochizuki, Yoshinori Tokura

    Advanced Materials   36 ( 1 ) 2306441  2024.01  [Refereed]  [International journal]

    　View Summary

    Abstract

    The spontaneous formation and topological transitions of vortex‐antivortex pairs have implications for a broad range of emergent phenomena, for example, from superconductivity to quantum computing. Unlike magnets exhibiting collinear spin textures, helimagnets with noncollinear spin textures provide unique opportunities to manipulate topological forms such as (anti)merons and (anti)skyrmions. However, it is challenging to achieve multiple topological states and their interconversion in a single helimagnet due to the topological protection for each state. Here, the on‐demand creation of multiple topological states in a helimagnet Fe0.5Co0.5Ge, including a spontaneous vortex pair of meron with topological charge N = −1/2 and antimeron with N = 1/2, and a vortex‐antivortex bundle, that is, a bimeron (meron pair) with N = −1 is reported. The mutual transformation between skyrmions and bimerons with respect to the competitive effects of magnetic field and magnetic shape anisotropy is demonstrated. It is shown that electric currents drive the individual bimerons to form their connecting assembly and then into a skyrmion lattice. These findings signify the feasibility of designing topological states and offer new insights into the manipulation of noncollinear spin textures for potential applications in various fields.

    DOI

    Scopus

    11
    Citation
    (Scopus)

  • Chiral Skyrmions Interacting with Chiral Flowers

    Xichao Zhang, Jing Xia, Oleg A. Tretiakov, Motohiko Ezawa, Guoping Zhao, Yan Zhou, Xiaoxi Liu, Masahito Mochizuki

    Nano Letters   23 ( 24 ) 11793 - 11801  2023.12  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • Laminar and transiently disordered dynamics of magnetic-skyrmion pipe flow

    Xichao Zhang, Jing Xia, Oleg A. Tretiakov, Motohiko Ezawa, Guoping Zhao, Yan Zhou, Xiaoxi Liu, Masahito Mochizuki

    Physical Review B   108 ( 14 ) 144428  2023.10  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Reversible magnetic domain reorientation induced by magnetic field pulses of fixed direction

    Xichao Zhang, Jing Xia, Oleg A. Tretiakov, Guoping Zhao, Yan Zhou, Masahito Mochizuki, Xiaoxi Liu, Motohiko Ezawa

    Physical Review B   108 ( 6 ) 064410  2023.08  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Current-Induced Helicity Switching of Frustrated Skyrmions on a Square-Grid Obstacle Pattern

    X. Zhang, J. Xia, O. A. Tretiakov, H. T. Diep, G. Zhao, J. Yang, Y. Zhou, M. Ezawa, X. Liu

    Journal of the Magnetics Society of Japan   47 ( 1 ) 20 - 27  2023.01  [Refereed]  [Domestic journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Reversible Transformation between Isolated Skyrmions and Bimerons

    Kentaro Ohara, Xichao Zhang, Yinling Chen, Satoshi Kato, Jing Xia, Motohiko Ezawa, Oleg A. Tretiakov, Zhipeng Hou, Yan Zhou, Guoping Zhao, Jinbo Yang, Xiaoxi Liu

    Nano Letters   22 ( 21 ) 8559 - 8566  2022.10  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author, Corresponding author

    DOI

    Scopus

    32
    Citation
    (Scopus)

  • Particle-like skyrmions interacting with a funnel obstacle

    Xichao Zhang, Jing Xia, Xiaoxi Liu

    Physical Review B   106 ( 9 ) 094418  2022.09  [Refereed]  [International journal]

    Authorship：Lead author

    DOI

  • Bifurcation of a topological skyrmion string

    Jing Xia, Xichao Zhang, Oleg A. Tretiakov, Hung T. Diep, Jinbo Yang, Guoping Zhao, Motohiko Ezawa, Yan Zhou, Xiaoxi Liu

    Physical Review B   105 ( 21 ) 214402  2022.06  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Structural transition of skyrmion quasiparticles under compression

    Xichao Zhang, Jing Xia, Xiaoxi Liu

    Physical Review B   105 ( 18 ) 184402  2022.05  [Refereed]  [International journal]

    Authorship：Lead author

    DOI

  • Exchange-Torque-Triggered Fast Switching of Antiferromagnetic Domains

    Jia Xu, Jing Xia, Xichao Zhang, Chao Zhou, Dong Shi, Haoran Chen, Tong Wu, Qian Li, Haifeng Ding, Yan Zhou, Yizheng Wu

    Physical Review Letters   128 ( 13 ) 137201  2022.04  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Dynamic transformation between a skyrmion string and a bimeron string in a layered frustrated system

    Xichao Zhang, Jing Xia, Oleg A. Tretiakov, Hung T. Diep, Guoping Zhao, Jinbo Yang, Yan Zhou, Motohiko Ezawa, Xiaoxi Liu

    Physical Review B   104 ( 22 ) L220406  2021.12  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Configurable pixelated skyrmions on nanoscale magnetic grids

    Xichao Zhang, Jing Xia, Keiichiro Shirai, Hiroshi Fujiwara, Oleg A. Tretiakov, Motohiko Ezawa, Yan Zhou, Xiaoxi Liu

    Communications Physics   4 ( 1 ) 255  2021.12  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    <title>Abstract</title>Topological spin textures can serve as non-volatile information carriers. Here we study the current-induced dynamics of an isolated magnetic skyrmion on a nanoscale square-grid pinning pattern formed by orthogonal defect lines with reduced magnetic anisotropy. The skyrmion on the square grid can be pixelated with a quantized size of the grid. We demonstrate that the position, size, and shape of skyrmion on the square grid are electrically configurable. The skyrmion center is quantized to be on the grid and the skyrmion may show a hopping motion instead of a continuous motion. We find that the skyrmion Hall effect can be perfectly prohibited due to the pinning effect of the grid. The pixelated skyrmion can be harnessed to build future programmable racetrack memory, multistate memory, and logic computing device. Our results will be a basis for digital information storage and computation based on pixelated topological spin textures on artificial pinning patterns.

    DOI

    Scopus

    16
    Citation
    (Scopus)

  • Confinement and Protection of Skyrmions by Patterns of Modified Magnetic Properties

    Kentaro Ohara, Xichao Zhang, Yinling Chen, Zonhan Wei, Yungui Ma, Jing Xia, Yan Zhou, Xiaoxi Liu

    Nano Letters   21 ( 10 ) 4320 - 4326  2021.05  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    47
    Citation
    (Scopus)

  • Current-induced dynamics of skyrmion tubes in synthetic antiferromagnetic multilayers

    Jing Xia, Xichao Zhang, Kai-Yu Mak, Motohiko Ezawa, Oleg A. Tretiakov, Yan Zhou, Guoping Zhao, Xiaoxi Liu

    Physical Review B   103 ( 17 ) 174408  2021.05  [Refereed]  [International coauthorship]

    Authorship：Lead author

    DOI

  • A frustrated bimeronium: Static structure and dynamics

    Xichao Zhang, Jing Xia, Motohiko Ezawa, Oleg A. Tretiakov, Hung T. Diep, Guoping Zhao, Xiaoxi Liu, Yan Zhou

    Applied Physics Letters   118 ( 5 ) 052411 - 052411  2021.02  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    We show a topological spin texture called "bimeronium" in magnets with in-plane magnetization. It is a topological counterpart of skyrmionium in perpendicularly magnetized magnets and can be seen as a combination of two bimerons with opposite topological charges. We report the static structure and spin-orbit-torque-induced dynamics of an isolated bimeronium in a magnetic monolayer with frustrated exchange interactions. We study the anisotropy and magnetic field dependences of a static bimeronium. We also explore the bimeronium dynamics driven by the damping-like spin-orbit torque. We find that the bimeronium shows steady rotation when the spin polarization direction is parallel to the easy axis. Moreover, we demonstrate the annihilation of the bimeronium when the spin polarization direction is perpendicular to the easy axis. Our results are useful for understanding the fundamental properties of bimeronium structures and may offer an approach to build bimeronium-based spintronic devices.

    DOI

    Scopus

    24
    Citation
    (Scopus)

  • Topology-Dependent Brownian Gyromotion of a Single Skyrmion

    Le Zhao, Zidong Wang, Xichao Zhang, Xue Liang, Jing Xia, Keyu Wu, Heng-An Zhou, Yiqing Dong, Guoqiang Yu, Kang L. Wang, Xiaoxi Liu, Yan Zhou, Wanjun Jiang

    Physical Review Letters   125 ( 2 ) 027206  2020.07  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Current-driven skyrmionium in a frustrated magnetic system

    Jing Xia, Xichao Zhang, Motohiko Ezawa, Oleg A. Tretiakov, Zhipeng Hou, Wenhong Wang, Guoping Zhao, Xiaoxi Liu, Hung T. Diep, Yan Zhou

    Applied Physics Letters   117 ( 1 ) 012403 - 012403  2020.07  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    Magnetic skyrmionium can be used as a nanometer-scale non-volatile information carrier, which shows no skyrmion Hall effect due to its special structure carrying zero topological charge. Here, we report the static and dynamic properties of an isolated nanoscale skyrmionium in a frustrated magnetic monolayer, where the skyrmionium is stabilized by competing interactions. The frustrated skyrmionium has a size of about 10nm, which can be further reduced by tuning perpendicular magnetic anisotropy or the magnetic field. It is found that the nanoscale skyrmionium driven by the damping-like spin-orbit torque shows directional motion with a favored Bloch-type helicity. A small driving current or magnetic field can lead to the transformation of an unstable Neel-type skyrmionium to a metastable Bloch-type skyrmionium. A large driving current may result in the distortion and collapse of the Bloch-type skyrmionium. Our results are useful for the understanding of frustrated skyrmionium physics, which also provide guidelines for the design of spintronic devices based on topological spin textures.

    DOI

    Scopus

    34
    Citation
    (Scopus)

  • Static and dynamic properties of bimerons in a frustrated ferromagnetic monolayer

    Xichao Zhang, Jing Xia, Laichuan Shen, Motohiko Ezawa, Oleg A. Tretiakov, Guoping Zhao, Xiaoxi Liu, Yan Zhou

    Physical Review B   101 ( 14 ) 144435  2020.04  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Skyrmion-electronics: writing, deleting, reading and processing magnetic skyrmions toward spintronic applications

    Xichao Zhang, Yan Zhou, Kyung Mee Song, Tae-Eon Park, Jing Xia, Motohiko Ezawa, Xiaoxi Liu, Weisheng Zhao, Guoping Zhao, Seonghoon Woo

    Journal of Physics: Condensed Matter   32 ( 14 ) 143001 - 143001  2020.04  [Refereed]  [Invited]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Dynamics of an elliptical ferromagnetic skyrmion driven by the spin–orbit torque

    Jing Xia, Xichao Zhang, Motohiko Ezawa, Qiming Shao, Xiaoxi Liu, Yan Zhou

    Applied Physics Letters   116 ( 2 ) 022407 - 022407  2020.01  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    31
    Citation
    (Scopus)

  • Current‐Induced Helicity Reversal of a Single Skyrmionic Bubble Chain in a Nanostructured Frustrated Magnet

    Zhipeng Hou, Qiang Zhang, Xichao Zhang, Guizhou Xu, Jing Xia, Bei Ding, Hang Li, Senfu Zhang, Nitin M. Batra, Pedro M. F. J. Costa, Enke Liu, Guangheng Wu, Motohiko Ezawa, Xiaoxi Liu, Yan Zhou, Xixiang Zhang, Wenhong Wang

    Advanced Materials   32 ( 1 ) 1904815 - 1904815  2020.01  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    59
    Citation
    (Scopus)

  • Generation and Hall effect of skyrmions enabled using nonmagnetic point contacts

    Zidong Wang, Xichao Zhang, Jing Xia, Le Zhao, Keyu Wu, Guoqiang Yu, Kang L. Wang, Xiaoxi Liu, Suzanne G. E. te Velthuis, Axel Hoffmann, Yan Zhou, Wanjun Jiang

    Physical Review B   100 ( 18 )  2019.11  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Current-Driven Dynamics of Frustrated Skyrmions in a Synthetic Antiferromagnetic Bilayer

    Jing Xia, Xichao Zhang, Motohiko Ezawa, Zhipeng Hou, Wenhong Wang, Xiaoxi Liu, Yan Zhou

    Physical Review Applied   11 ( 4 ) 044046  2019.04  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Manipulation of magnetic skyrmions in a locally modified synthetic antiferromagnetic racetrack

    R.P. Loreto, X. Zhang, Y. Zhou, M. Ezawa, X. Liu, C.I.L. de Araujo

    Journal of Magnetism and Magnetic Materials   482   155 - 159  2019.03  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    10
    Citation
    (Scopus)

  • Electric Field-Induced Creation and Directional Motion of Domain Walls and Skyrmion Bubbles

    Chuang Ma, Xichao Zhang, Jing Xia, Motohiko Ezawa, Wanjun Jiang, Teruo Ono, S. N. Piramanayagam, Akimitsu Morisako, Yan Zhou, Xiaoxi Liu

    Nano Letters   19 ( 1 ) 353 - 361  2019.01  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    Magnetization dynamics driven by an electric field could provide long-term benefits to information technologies because of its ultralow power consumption. Meanwhile, the Dzyaloshinskii-Moriya interaction in interfacially asymmetric multilayers consisting of ferromagnetic and heavy-metal layers can stabilize topological spin textures, such as chiral domain walls, skyrmions, and skyrmion bubbles. These topological spin textures can be controlled by an electric field and hold promise for building advanced spintronic devices. Here, we present an experimental and numerical study on the electric field-induced creation and directional motion of topological spin textures in magnetic multilayer films and racetracks with thickness gradient and interfacial Dzyaloshinskii-Moriya interaction at room temperature. We find that the electric field-induced directional motion of chiral domain wall is accompanied by the creation of skyrmion bubbles at certain conditions. We also demonstrate that the electric field variation can induce motion of skyrmion bubbles. Our findings may provide opportunities for developing skyrmion-based devices with ultralow power consumption.

    DOI PubMed

    Scopus

    107
    Citation
    (Scopus)

  • Deterministic creation and deletion of a single magnetic skyrmion observed by direct time-resolved X-ray microscopy

    Seonghoon Woo, Kyung Mee Song, Xichao Zhang, Motohiko Ezawa, Yan Zhou, Xiaoxi Liu, Markus Weigand, Simone Finizio, Jörg Raabe, Min-Chul Park, Ki-Young Lee, Jun Woo Choi, Byoung-Chul Min, Hyun Cheol Koo, Joonyeon Chang

    Nature Electronics   1 ( 5 ) 288 - 296  2018.05  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    119
    Citation
    (Scopus)

  • Skyrmion dynamics in a frustrated ferromagnetic film and current-induced helicity locking-unlocking transition

    Xichao Zhang, Jing Xia, Yan Zhou, Xiaoxi Liu, Han Zhang, Motohiko Ezawa

    Nature Communications   8 ( 1 ) 1717  2017.12  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    The helicity-orbital coupling is an intriguing feature of magnetic skyrmions in frustrated magnets. Here we explore the skyrmion dynamics in a frustrated magnet based on the J(1)-J(2)-J(3) classical Heisenberg model explicitly by including the dipole-dipole interaction. The skyrmion energy acquires a helicity dependence due to the dipole-dipole interaction, resulting in the current-induced translational motion with a fixed helicity. The lowest-energy states are the degenerate Bloch-type states, which can be used for building the binary memory. By increasing the driving current, the helicity locking-unlocking transition occurs, where the translational motion changes to the rotational motion. Furthermore, we demonstrate that two skyrmions can spontaneously form a bound state. The separation of the bound state forced by a driving current is also studied. In addition, we show the annihilation of a pair of skyrmion and antiskyrmion. Our results reveal the distinctive frustrated skyrmions may enable viable applications in topological magnetism.

    DOI

    Scopus

    165
    Citation
    (Scopus)

  • Motion of skyrmions in nanowires driven by magnonic momentum-transfer forces

    Xichao Zhang, Jan Müller, Jing Xia, Markus Garst, Xiaoxi Liu, Yan Zhou

    New Journal of Physics   19 ( 6 ) 065001 - 065001  2017.06  [Refereed]  [Invited]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    57
    Citation
    (Scopus)

  • Direct observation of the skyrmion Hall effect

    Wanjun Jiang, Xichao Zhang, Guoqiang Yu, Wei Zhang, Xiao Wang, M. Benjamin Jungfleisch, John E. Pearson, Xuemei Cheng, Olle Heinonen, Kang L. Wang, Yan Zhou, Axel Hoffmann, Suzanne G. E. te Velthuis

    Nature Physics   13 ( 2 ) 162 - 169  2017.02  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    984
    Citation
    (Scopus)

  • Magnetic Skyrmion Transport in a Nanotrack With Spatially Varying Damping and Non-adiabatic Torque

    Xichao Zhang, Jing Xia, G.P. Zhao, Xiaoxi Liu, Yan Zhou

    IEEE Transactions on Magnetics   53 ( 3 ) 1500206  2016.12  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

  • Control and manipulation of a magnetic skyrmionium in nanostructures

    Xichao Zhang, Jing Xia, Yan Zhou, Daowei Wang, Xiaoxi Liu, Weisheng Zhao, Motohiko Ezawa

    Physical Review B   94 ( 9 ) 094420  2016.09  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    A magnetic skyrmionium is a nontopological soliton, which has a doughnut-like out-of-plane spin texture in thin films, and can be phenomenologically viewed as a coalition of two topological magnetic skyrmions with opposite topological numbers. Due to its zero topological number (Q = 0) and doughnut-like structure, the skyrmionium has its distinctive characteristics as compared to the skyrmion with Q = +/- 1. Here we systematically study the generation, manipulation, and motion of a skyrmionium in ultrathin magnetic nanostructures by applying a magnetic field or a spin-polarized current. It is found that the skyrmionium moves faster than the skyrmion when they are driven by the out-of-plane current, and their velocity difference is proportional to the driving force. However, the skyrmionium and skyrmion exhibit an identical current-velocity relation when they are driven by the in-plane current. It is also found that a moving skyrmionium is less deformed in the current-in-plane geometry compared with the skyrmionium in the current-perpendicular-to-plane geometry. Furthermore we demonstrate the transformation of a skyrmionium with Q = 0 into two skyrmions with Q = +1 in a nanotrack driven by a spin-polarized current, which can be seen as the unzipping process of a skyrmionium. We illustrate the energy and spin structure variations during the skyrmionium unzipping process, where linear relations between the spin structure and energies are found. These results could have technological implications in the emerging field of skyrmionics.

    DOI

  • Thermally stable magnetic skyrmions in multilayer synthetic antiferromagnetic racetracks

    Xichao Zhang, Motohiko Ezawa, Yan Zhou

    Physical Review B   94 ( 6 ) 064406  2016.08  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    A magnetic skyrmion is a topological magnetization structure with a nanometric size and a well-defined swirling spin distribution, which is anticipated to be an essential building block for novel skyrmion-based device applications. We study the motion of magnetic skyrmions in multilayer synthetic antiferromagnetic (SAF) racetracks as well as in conventional monolayer ferromagnetic (FM) racetracks at finite temperature. There is an odd-even effect of the constituent FM layer number on the skyrmion Hall effect (SkHE). Namely, due to the suppression of the SkHE, the magnetic skyrmion has no transverse motion in multilayer SAF racetracks packed with even FM layers. It is shown that a moving magnetic skyrmion is stable even at room temperature (T = 300 K) in a bilayer SAF racetrack but it is destructed at T = 100 K in a monolayer FM racetrack. Our results indicate that the SAF structures are reliable and promising candidates for future applications in skyrmion electronics and skyrmion spintronics.

    DOI

  • Antiferromagnetic Skyrmion: Stability, Creation and Manipulation

    Xichao Zhang, Yan Zhou, Motohiko Ezawa

    Scientific Reports   6 ( 1 ) 24795  2016.04  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    Magnetic skyrmions are particle-like topological excitations in ferromagnets, which have the topological number Q = +/- 1, and hence show the skyrmion Hall effect (SkHE) due to the Magnus force effect originating from the topology. Here, we propose the counterpart of the magnetic skyrmion in the antiferromagnetic (AFM) system, that is, the AFM skyrmion, which is topologically protected but without showing the SkHE. Two approaches for creating the AFM skyrmion have been described based on micromagnetic lattice simulations: (i) by injecting a vertical spin-polarized current to a nanodisk with the AFM ground state; (ii) by converting an AFM domain-wall pair in a nanowire junction. It is demonstrated that the AFM skyrmion, driven by the spin-polarized current, can move straightly over long distance, benefiting from the absence of the SkHE. Our results will open a new strategy on designing the novel spintronic devices based on AFM materials.

    DOI

    Scopus

    339
    Citation
    (Scopus)

  • High-topological-number magnetic skyrmions and topologically protected dissipative structure

    Xichao Zhang, Yan Zhou, Motohiko Ezawa

    Physical Review B   93 ( 2 ) 024415  2016.01  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    The magnetic skyrmion with the topological number of unity (Q = 1) is a well-known nanometric swirling spin structure in the nonlinear sigma model with the Dzyaloshinskii-Moriya interaction. Here we show that magnetic skyrmion with the topological number of two (Q = 2) can be created and stabilized by applying vertical spin-polarized current though it cannot exist as a static stable excitation. Magnetic skyrmion with Q = 2 is a nonequilibrium dynamic object, subsisting on a balance between the energy injection from the current and the energy dissipation by the Gilbert damping. Once it is created, it becomes a topologically protected object against fluctuations of various variables including the injected current itself. Hence we may call it a topologically protected dissipative structure. We also elucidate the nucleation and destruction mechanisms of the magnetic skyrmion with Q = 2 by studying the evolutions of the magnetization distribution, the topological charge density, as well as the energy density. Our results will be useful for the study of the nontrivial topology of magnetic skyrmions with higher topological numbers.

    DOI

  • Magnetic bilayer-skyrmions without skyrmion Hall effect

    Xichao Zhang, Yan Zhou, Motohiko Ezawa

    Nature Communications   7 ( 1 ) 10293  2016.01  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    Magnetic skyrmions might be used as information carriers in future advanced memories, logic gates and computing devices. However, there exists an obstacle known as the skyrmion Hall effect (SkHE), that is, the skyrmion trajectories bend away from the driving current direction due to the Magnus force. Consequently, the skyrmions in constricted geometries may be destroyed by touching the sample edges. Here we theoretically propose that the SkHE can be suppressed in the antiferromagnetically exchange-coupled bilayer system, since the Magnus forces in the top and bottom layers are exactly cancelled. We show that such a pair of SkHE-free magnetic skyrmions can be nucleated and be driven by the current-induced torque. Our proposal provides a promising means to move magnetic skyrmions in a perfectly straight trajectory in ultra-dense devices with ultra-fast processing speed.

    DOI

    Scopus

    477
    Citation
    (Scopus)

  • Magnetic skyrmion transistor: skyrmion motion in a voltage-gated nanotrack

    Xichao Zhang, Yan Zhou, Motohiko Ezawa, G. P. Zhao, Weisheng Zhao

    Scientific Reports   5 ( 1 ) 11369  2015.06  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    Magnetic skyrmions are localized and topologically protected spin configurations, which are of both fundamental and applied interests for future electronics. In this work, we propose a voltage-gated skyrmion transistor within the well-established framework of micromagnetics. Its operating conditions and processes have been theoretically investigated and demonstrated, in which the gate voltage can be used to switch on/off a circuit. Our results provide the first time guidelines for practical realization of hybrid skyrmionic-electronic devices.

    DOI

    Scopus

    245
    Citation
    (Scopus)

  • All-magnetic control of skyrmions in nanowires by a spin wave

    Xichao Zhang, Motohiko Ezawa, Dun Xiao, G P Zhao, Yaowen Liu, Yan Zhou

    Nanotechnology   26 ( 22 ) 225701  2015.05  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    　View Summary

    Magnetic skyrmions are topologically protected nanoscale objects, which are promising building blocks for novel magnetic and spintronic devices. Here, we investigate the dynamics of a skyrmion driven by a spin wave in a magnetic nanowire. It is found that (i) the skyrmion is first accelerated and then decelerated exponentially; (ii) it can turn L-corners with both right and left turns; and (iii) it always turns left (right) when the skyrmion number is positive (negative) in the T-and Y-junctions. Our results will be the basis of skyrmionic devices driven by a spin wave.

    DOI

    Scopus

    119
    Citation
    (Scopus)

  • Magnetic skyrmion logic gates: conversion, duplication and merging of skyrmions

    Xichao Zhang, Motohiko Ezawa, Yan Zhou

    Scientific Reports   5 ( 1 ) 9400  2015.03  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    667
    Citation
    (Scopus)

  • Skyrmion-skyrmion and skyrmion-edge repulsions in skyrmion-based racetrack memory

    Xichao Zhang, G. P. Zhao, Hans Fangohr, J. Ping Liu, W. X. Xia, J. Xia, F. J. Morvan

    Scientific Reports   5 ( 1 ) 7643  2015.01  [Refereed]  [International journal]  [International coauthorship]

    Authorship：Lead author

    DOI

    Scopus

    411
    Citation
    (Scopus)

  • Micromagnetic simulation of Sm—Co/α-Fe/Sm—Co trilayers with various angles between easy axes and the film plane

    Xi-Chao Zhang, Guo-Ping Zhao, Jing Xia, Ming Yue, Xin-Hong Yuan, Lin-Hua Xie

    Chinese Physics B   23 ( 9 ) 097504  2014.07  [Refereed]  [International journal]

    Authorship：Lead author

    DOI

    Scopus

    14
    Citation
    (Scopus)

  • Micromagnetic analysis of the maghemite platelet chains in the iron-mineral-based magnetoreceptor of birds

    Zhang Xi-Chao, Zhao Guo-Ping, Xia Jing

    Acta Physica Sinica   62 ( 21 ) 218702  2013.11  [Refereed]

    Authorship：Lead author

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Fundamentals and applications of the skyrmion Hall effect

    Sheng Yang, Yuelei Zhao, Xichao Zhang, Xiangjun Xing, Haifeng Du, Xiaoguang Li, Masahito Mochizuki, Xiaohong Xu, Johan Åkerman, Yan Zhou

    Applied Physics Reviews   11   041335/1 - 28  2024.12  [Refereed]  [International journal]  [International coauthorship]

    DOI

    Scopus

  • Suppression of the skyrmion Hall effect in synthetic ferrimagnets with gradient magnetization

    Lan Bo, Xichao Zhang, Masahito Mochizuki, Xuefeng Zhang

    Physical Review Research   6 ( 2 ) 023199  2024.05  [Refereed]  [International journal]  [International coauthorship]

    　View Summary

    Magnetic skyrmions are promising building blocks for future spintronic devices. However, the skyrmion Hall effect (SkHE) remains an obstacle for practical applications based on the in-line transport of skyrmions. Here, we numerically study the static properties and current-driven dynamics of synthetic ferrimagnetic skyrmions. Inspired by graded-index magnonics, we introduce a linear gradient of saturation magnetization (Ms) in the skyrmion-hosting sample, which effectively modulates the skyrmion Hall angle and suppresses the SkHE. Micromagnetic simulations reveal that ferrimagnetic skyrmions could exhibit greater susceptibility to the variation of Ms as compared to their ferromagnetic counterparts. The Thiele analysis is also applied to support the simulation results, which elucidates that the Ms gradient dynamically modifies the intrinsic normalized size of skyrmions, consequently impacting the SkHE. Our results pave the way to the graded-index skyrmionics, which offers novel insights for designing ferrimagnet-based skyrmionic devices.

    Published by the American Physical Society 2024

    DOI

  • Universal quantum computing based on magnetic domain-wall qubits

    Shuang Li, Xichao Zhang, Motohiko Ezawa, Yan Zhou

    Materials Today Quantum   2   100005 - 100005  2024.04  [Refereed]  [Invited]  [International journal]  [International coauthorship]

    DOI

  • Transformation of a skyrmionium to a skyrmion through the thermal annihilation of the inner skyrmion

    Anjie Jiang, Yan Zhou, Xichao Zhang, Masahito Mochizuki

    Physical Review Research   6 ( 1 ) 013229  2024.03  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Global rotation of skyrmion bags under vertical microwave fields

    Lan Bo, Rongzhi Zhao, Xichao Zhang, Masahito Mochizuki, Xuefeng Zhang

    Journal of Applied Physics   135 ( 6 ) 063905  2024.02  [Refereed]  [International journal]  [International coauthorship]

    　View Summary

    Magnetic skyrmion bags are composite topological spin textures with arbitrary topological charges. Here, we computationally study the transient rotational motion of skyrmion bags, which is characterized by a global rotation of inner skyrmions around the central point. Distinct from conventional rotational modes found in skyrmions, the observed rotation is a forced motion associated with the breathing mode induced solely by vertical microwave fields. The driving force behind this rotation originates from the interactions between outer and inner skyrmions, with the angular velocity determined by the phase difference resulting from their asynchronous breathing behaviors. It is also found that skyrmion bags with larger skyrmion numbers are more conducive to the occurrence of the rotation. Our results are useful for understanding the cluster dynamics of complex topological spin textures driven by dynamic fields.

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • Identifying and Exploring Synthetic Antiferromagnetic Skyrmions

    Yuelei Zhao, Sheng Yang, Kai Wu, Shuang Li, Yang Gao, Hongyuan Hao, Xichao Zhang, Shouguo Wang, Qingfang Liu, Senfu Zhang, Zhiqin Chu, Johan Åkerman, Yan Zhou

    Advanced Functional Materials   33   2303133  2023.12

    　View Summary

    Abstract

    Synthetic antiferromagnetic (SAF) skyrmions are emerging as novel information carriers due to their high mobility and lack of a skyrmion Hall effect. However, distinguishing SAF skyrmions from their ferromagnetic counterparts using imaging techniques like magneto‐optical microscopy remains challenging. While the suppressed intrinsic skyrmion Hall effect (SkHE) has been commonly used to identify SAF skyrmions, it is important to note that other factors such as defect pinning and dipolar interaction can also lead to a suppressed SkHE. Therefore, there is an urgent need for a universal identification method that can reliably differentiate SAF skyrmions from ferromagnetic ones. In this study, the generation of a SAF skyrmion within a standard SAF stack is demonstrated and its motion with almost no SkHE is investigated. Furthermore, a universal identification method is proposed wherein the application of an out‐of‐plane field allows the SAF skyrmion to be decoupled into two domains, which can either expand or contract with the application of an electric current. By expediting the development of a reliable means of identifying SAF skyrmions, these findings will accelerate the realization of practical applications based on these unique information carriers.

    DOI

    Scopus

    4
    Citation
    (Scopus)

  • Topology-induced chiral photon emission from a large-scale meron lattice

    Xuefeng Wu, Xu Li, Wenyu Kang, Xichao Zhang, Li Chen, Zhibai Zhong, Yan Zhou, Johan Åkerman, Yaping Wu, Rong Zhang, Junyong Kang

    Nature Electronics   6 ( 7 ) 516 - 524  2023.07  [Refereed]  [International journal]  [International coauthorship]

    　View Summary

    Abstract

    Merons are a class of topologically protected particle-like structures created in in-plane magnetized magnetic films. The structures can act as information carriers and could be used for magnetic storage. However, the development of such applications is hampered by limitations in the size, thermal stability and magnetic-field requirements of the systems. Here we report the construction of millimetre-scale meron lattices that are stable at room temperature and under zero magnetic field. Our system is based on a trilayer structure composed of a thin iron film sandwiched between films of palladium and magnesium oxide (Pd/Fe/MgO) on a gallium nitride wafer. It is fabricated using a molecular-beam epitaxy approach that is assisted by a high magnetic field, which leads to a strong Dzyaloshinskii–Moriya interaction. The lattices can be used for chirality transfer from merons to electrons and then to photons, and we show that the meron lattices can be used as spin injectors in nitride-based light-emitting diodes. The topology-induced spin light-emitting diode can provide 22.5% circularly polarized electroluminescence at room temperature and under zero magnetic field.

    DOI

    Scopus

    9
    Citation
    (Scopus)

  • Controllable creation of skyrmion bags in a ferromagnetic nanodisk

    Lan Bo, Rongzhi Zhao, Chenglong Hu, Xichao Zhang, Xuefeng Zhang, Masahito Mochizuki

    Physical Review B   107 ( 22 ) 224431  2023.06  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Universal Quantum Computation Based on Nanoscale Skyrmion Helicity Qubits in Frustrated Magnets

    Jing Xia, Xichao Zhang, Xiaoxi Liu, Yan Zhou, Motohiko Ezawa

    Physical Review Letters   130 ( 10 )  2023.03  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Elimination of the skyrmion Hall effect by tuning perpendicular magnetic anisotropy and spin polarization angle

    J.H. Guo, Y. Hou, X. Zhang, Philip W.T. Pong, Y. Zhou

    Physics Letters A   456   128497 - 128497  2022.12  [Refereed]  [International journal]  [International coauthorship]

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • Systematic Control of the Interlayer Exchange Coupling in Perpendicularly Magnetized Synthetic Antiferromagnets

    Teng Xu, Jiahao Liu, Xichao Zhang, Qihan Zhang, Heng-An Zhou, Yiqing Dong, Pierluigi Gargiani, Manuel Valvidares, Yan Zhou, Wanjun Jiang

    Physical Review Applied   18 ( 5 )  2022.11  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Qubits based on merons in magnetic nanodisks

    Jing Xia, Xichao Zhang, Xiaoxi Liu, Yan Zhou, Motohiko Ezawa

    Communications Materials   3 ( 1 )  2022.11  [Refereed]  [International journal]  [International coauthorship]

    　View Summary

    Abstract

    A meron is a classical topological soliton having a half topological charge. It could be materialized in a magnetic disk. However, it will become a quantum mechanical object when its size is of the order of nanometers. Here, we propose to use a nanoscale meron in a magnetic nanodisk as a qubit, where the up and down directions of the core spin are assigned to be the qubit states $$\left\vert 0\right\rangle$$ and $$\left\vert 1\right\rangle$$. We first numerically show that a meron with the radius containing as small as 7 spins can be stabilized in a ferromagnetic nanodisk classically. Then, we show theoretically that universal quantum computation is possible based on merons by explicitly constructing the arbitrary phase-shift gate, Hadamard gate, and CNOT gate. They are executed by applying a magnetic field or spin-polarized current. Our results may be useful for the implementation of quantum computation based on topological spin textures in nanomagnets.

    DOI

    Scopus

    27
    Citation
    (Scopus)

  • Nonlinear dynamics of the topological helicity wave in a frustrated skyrmion string

    Jing Xia, Xichao Zhang, Xiaoxi Liu, Yan Zhou, Motohiko Ezawa

    Physical Review B   106 ( 5 ) 054414  2022.08  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Dynamics of magnetic skyrmions driven by a temperature gradient in a chiral magnet FeGe

    Gang Qin, Xichao Zhang, Ruixuan Zhang, Ke Pei, Chendi Yang, Chunyang Xu, Yan Zhou, Yizheng Wu, Haifeng Du, Renchao Che

    Physical Review B   106 ( 2 ) 024415  2022.07  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Controlling domain wall and field-free spin–orbit torque switching in synthetic antiferromagnets

    Yuelei Zhao, Sheng Yang, Kai Wu, Xiaoguang Li, Xichao Zhang, Li Li, Zhiqin Chu, Chong Bi, Yan Zhou

    Applied Physics Letters   120 ( 22 ) 222401 - 222401  2022.05  [Refereed]  [International journal]  [International coauthorship]

    　View Summary

    Perpendicular magnetization switching driven by spin–orbit torques plays an increasingly important role for spintronic devices toward practical applications but is also hindered by the well-known technical challenge that an external in-plane magnetic field is required for deterministic switching. Here, we show that the deterministic switching can be achieved in synthetic antiferromagnets through the flexible domain control in the absence of external magnetic fields. Specifically, we have observed that the domain wall (DW) distorts under an applied electric current in contrast to the conventional rigid DW motion in a single ferromagnet. More importantly, the distorted DWs can be precisely controlled under zero magnetic field, leading to the deterministic switching. Our results indicate that the critical technical challenge may be addressed by employing a synthetic antiferromagnetic layer through the DW motion dominated field-free switching.

    DOI

    Scopus

    2
    Citation
    (Scopus)

  • Mutual conversion between a magnetic Néel hopfion and a Néel toron

    Shuang Li, Jing Xia, Laichuan Shen, Xichao Zhang, Motohiko Ezawa, Yan Zhou

    Physical Review B   105 ( 17 ) 174407  2022.05  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Single-bit full adder and logic gate based on synthetic antiferromagnetic bilayer skyrmions

    Kai Yu Mak, Jing Xia, Xi-Chao Zhang, Li Li, Mouad Fattouhi, Motohiko Ezawa, Xiao-Xi Liu, Yan Zhou

    Rare Metals    2022.04  [Refereed]  [Invited]  [International journal]  [International coauthorship]

    DOI

    Scopus

    8
    Citation
    (Scopus)

  • Controlled Switching of the Number of Skyrmions in a Magnetic Nanodot by Electric Fields

    Zhipeng Hou, Yadong Wang, Xiaoming Lan, Sai Li, Xuejin Wan, Fei Meng, Yangfan Hu, Zhen Fan, Chun Feng, Minghui Qin, Min Zeng, Xichao Zhang, Xiaoxi Liu, Xuewen Fu, Guanghua Yu, Guofu Zhou, Yan Zhou, Weisheng Zhao, Xingsen Gao, Jun‐ming Liu

    Advanced Materials   34 ( 11 ) 2107908 - 2107908  2022.03  [Refereed]  [International journal]  [International coauthorship]

    DOI

    Scopus

    30
    Citation
    (Scopus)

  • Dynamic properties of a ferromagnetic skyrmion in an in-plane magnetic field

    J. H. Guo, Y. Hou, J. Xia, X. Zhang, Philip W. T. Pong, Y. Zhou

    Journal of Applied Physics   131 ( 7 ) 073901 - 073901  2022.02  [Refereed]  [International journal]  [International coauthorship]

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Nonreciprocal dynamics of ferrimagnetic bimerons

    Laichuan Shen, Jing Xia, Zehan Chen, Xiaoguang Li, Xichao Zhang, Oleg A. Tretiakov, Qiming Shao, Guoping Zhao, Xiaoxi Liu, Motohiko Ezawa, Yan Zhou

    Physical Review B   105 ( 1 ) 014422  2022.01  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Skyrmion Dynamics in the Presence of Deformation

    Zehan Chen, Xichao Zhang, Yan Zhou, Qiming Shao

    Physical Review Applied   17 ( 1 ) L011002  2022.01  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Dynamics of ferrimagnetic skyrmionium driven by spin-orbit torque

    Xue Liang, Xichao Zhang, Laichuan Shen, Jing Xia, Motohiko Ezawa, Xiaoxi Liu, Yan Zhou

    Physical Review B   104 ( 17 ) 174421  2021.11  [Refereed]  [International coauthorship]

    DOI

  • Tunable Néel–Bloch Magnetic Twists in Fe3GeTe2 with van der Waals Structure

    Licong Peng, Fehmi S. Yasin, Tae‐Eon Park, Sung Jong Kim, Xichao Zhang, Takuro Nagai, Koji Kimoto, Seonghoon Woo, Xiuzhen Yu

    Advanced Functional Materials   31 ( 37 ) 2103583  2021.09  [Refereed]  [International coauthorship]

    DOI

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    47
    Citation
    (Scopus)

  • Antiferromagnetic skyrmion-based logic gates controlled by electric currents and fields

    Xue Liang, Jing Xia, Xichao Zhang, Motohiko Ezawa, Oleg A. Tretiakov, Xiaoxi Liu, Lei Qiu, Guoping Zhao, Yan Zhou

    Applied Physics Letters   119 ( 6 ) 062403 - 062403  2021.08  [Refereed]  [International journal]  [International coauthorship]

    DOI

    Scopus

    57
    Citation
    (Scopus)

  • Transcription and logic operations of magnetic skyrmions in bilayer cross structures

    Kai Yu Mak, Jing Xia, Xichao Zhang, Motohiko Ezawa, Xiaoxi Liu, Yan Zhou

    Journal of Physics: Condensed Matter   33 ( 40 ) 404001 - 404001  2021.07  [Refereed]  [Invited]  [International journal]  [International coauthorship]

    DOI

  • Logic Gates Based on Synthetic Antiferromagnetic Bilayer Skyrmions

    Mouad Fattouhi, Kai Yu Mak, Yan Zhou, Xichao Zhang, Xiaoxi Liu, Mohamed El Hafidi

    Physical Review Applied   16 ( 1 ) 014040  2021.07  [Refereed]  [International journal]  [International coauthorship]

    DOI

  • Domain wall dynamics in ferromagnet/Ru/ferromagnet stacks with a wedged spacer

    Yuelei Zhao, Sheng Yang, Jing Xia, Xiaoguang Li, Kai Wu, Yuqing Zhou, Kaiquan Fan, Xichao Zhang, Yan Zhou

    Applied Physics Letters   119 ( 2 ) 022406 - 022406  2021.07  [Refereed]  [International journal]  [International coauthorship]

    DOI

    Scopus

    5
    Citation
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  • Néel-type skyrmions and their current-induced motion in van der Waals ferromagnet-based heterostructures

    Tae-Eon Park, Licong Peng, Jinghua Liang, Ali Hallal, Fehmi Sami Yasin, Xichao Zhang, Kyung Mee Song, Sung Jong Kim, Kwangsu Kim, Markus Weigand, Gisela Schütz, Simone Finizio, Jörg Raabe, Karin Garcia, Jing Xia, Yan Zhou, Motohiko Ezawa, Xiaoxi Liu, Joonyeon Chang, Hyun Cheol Koo, Young Duck Kim, Mairbek Chshiev, Albert Fert, Hongxin Yang, Xiuzhen Yu, Seonghoon Woo

    Physical Review B   103 ( 10 )  2021.03  [Refereed]  [International journal]  [International coauthorship]

    　View Summary

    Since the discovery of ferromagnetic two-dimensional (2D) van der Waals (vdW) crystals, significant interest on such 2D magnets has emerged, inspired by their appealing physical properties and integration with other 2D family for unique heterostructures. In known 2D magnets, spin-orbit coupling (SOC) stabilizes perpendicular magnetic anisotropy down to one or a few monolayers. Such a strong SOC could also lift the chiral degeneracy, leading to the formation of topological magnetic textures such as skyrmions through the Dzyaloshinskii-Moriya interaction (DMI). Here, we report the experimental observation of Neel-type chiral magnetic skyrmions and their lattice (SkX) formation in a vdW ferromagnet Fe3GeTe2 (FGT). We demonstrate the ability to drive an individual skyrmion by short current pulses along a vdW heterostructure, FGT/h-BN, as highly required for any skyrmion-based spintronic device. Using first principle calculations supported by experiments, we unveil the origin of DMI being the interfaces with oxides, which then allows us to engineer vdW heterostructures for desired chiral states. Our finding opens the door to topological spin textures in the 2D vdW magnet and their potential device application.

    DOI

  • Interlayer coupling effect on skyrmion dynamics in synthetic antiferromagnets

    Lei Qiu, Laichuan Shen, Xichao Zhang, Yan Zhou, Guoping Zhao, Weixing Xia, Hu-Bin Luo, J. Ping Liu

    Applied Physics Letters    2021.02

    DOI

    Scopus

    11
    Citation
    (Scopus)

  • Magnetic skyrmions for unconventional computing

    Sai Li, Wang Kang, Xichao Zhang, Tianxiao Nie, Yan Zhou, Kang L. Wang, Weisheng Zhao

    Materials Horizons    2021

    DOI

  • A ferromagnetic skyrmion-based nano-oscillator with modified perpendicular magnetic anisotropy

    J.H. Guo, J. Xia, X. Zhang, Philip W.T. Pong, Y. Zhou

    Physics Letters A     127157 - 127157  2021.01

    DOI

    Scopus

    16
    Citation
    (Scopus)

  • Bimeron clusters in chiral antiferromagnets

    Xiaoguang Li, Laichuan Shen, Yuhao Bai, Junlin Wang, Xichao Zhang, Jing Xia, Motohiko Ezawa, Oleg A. Tretiakov, Xiaohong Xu, Michal Mruczkiewicz, Maciej Krawczyk, Yongbing Xu, Richard F. L. Evans, Roy W. Chantrell, Yan Zhou

    npj Computational Materials   6 ( 1 )  2020.12

    　View Summary

    A magnetic bimeron is an in-plane topological counterpart of a magnetic skyrmion. Despite the topological equivalence, their statics and dynamics could be distinct, making them attractive from the perspectives of both physics and spintronic applications. In this work, we demonstrate the stabilization of bimeron solitons and clusters in the antiferromagnetic (AFM) thin film with interfacial Dzyaloshinskii-Moriya interaction (DMI). Bimerons demonstrate high current-driven mobility as generic AFM solitons, while featuring anisotropic and relativistic dynamics excited by currents with in-plane and out-of-plane polarizations, respectively. Moreover, these spin textures can absorb other bimeron solitons or clusters along the translational direction to acquire a wide range of Neel topological numbers. The clustering involves the rearrangement of topological structures, and gives rise to remarkable changes in static and dynamical properties. The merits of AFM bimeron clusters reveal a potential path to unify multibit data creation, transmission, storage, and even topology-based computation within the same material system, and may stimulate spintronic devices enabling innovative paradigms of data manipulations.

    DOI

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    45
    Citation
    (Scopus)

  • Magnetic skyrmionium diode with a magnetic anisotropy voltage gating

    Junlin Wang, Jing Xia, Xichao Zhang, Xiangyu Zheng, Guanqi Li, Li Chen, Yan Zhou, Jing Wu, Haihong Yin, Roy Chantrell, Yongbing Xu

    Applied Physics Letters    2020.11

    DOI

    Scopus

    44
    Citation
    (Scopus)

  • Dynamics of ferromagnetic bimerons driven by spin currents and magnetic fields

    Laichuan Shen, Xiaoguang Li, Jing Xia, Lei Qiu, Xichao Zhang, Oleg A. Tretiakov, Motohiko Ezawa, Yan Zhou

    Physical Review B   102 ( 10 )  2020.09

    　View Summary

    A magnetic bimeron composed of two merons is a topological counterpart of a magnetic skyrmion in in-plane magnets, which can be used as the nonvolatile information carrier in spintronic devices. Here we analytically and numerically study the dynamics of ferromagnetic bimerons driven by spin currents and magnetic fields. Numerical simulations demonstrate that two bimerons with opposite signs of topological numbers can be created simultaneously in a ferromagnetic thin film via current-induced spin torques. The current-induced spin torques can also drive the bimeron and its speed is analytically derived, which agrees with the numerical results. Since the bimerons with opposite topological numbers can coexist and have opposite drift directions, two-lane racetracks can be built to accurately encode the data bits. In addition, the dynamics of bimerons induced by magnetic field gradients and alternating magnetic fields are investigated. It is found that the bimeron driven by alternating magnetic fields can propagate along a certain direction. Moreover, combining a suitable magnetic field gradient, the Magnus-force-induced transverse motion can be completely suppressed, which implies that there is no skyrmion Hall effect. Our results are useful for understanding the bimeron dynamics and may provide guidelines for building future bimeron-based spintronic devices.

    DOI

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    29
    Citation
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  • Electric-field-driven non-volatile multi-state switching of individual skyrmions in a multiferroic heterostructure

    Yadong Wang, Lei Wang, Jing Xia, Zhengxun Lai, Guo Tian, Xichao Zhang, Zhipeng Hou, Xingsen Gao, Wenbo Mi, Chun Feng, Min Zeng, Guofu Zhou, Guanghua Yu, Guangheng Wu, Yan Zhou, Wenhong Wang, Xi-xiang Zhang, Junming Liu

    Nature Communications   11 ( 1 )  2020.07

    DOI

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    150
    Citation
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  • Realization of isolated and high-density skyrmions at room temperature in uncompensated synthetic antiferromagnets

    Ruyi Chen, Yang Gao, Xichao Zhang, Ruiqi Zhang, Siqi Yin, Xianzhe Chen, Xiaofeng Zhou, Yongjian Zhou, Jing Xia, Yan Zhou, Shouguo Wang, Feng Pan, Ying Zhang, Cheng Song

    Nano Letters    2020.04

    DOI

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    57
    Citation
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  • A spiking neuron constructed by the skyrmion-based spin torque nano-oscillator

    Xue Liang, Xichao Zhang, Jing Xia, Motohiko Ezawa, Yuelei Zhao, Guoping Zhao, Yan Zhou

    Applied Physics Letters    2020.03

    DOI

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    48
    Citation
    (Scopus)

  • Skyrmion-based artificial synapses for neuromorphic computing

    Kyung Mee Song, Jae-Seung Jeong, Biao Pan, Xichao Zhang, Jing Xia, Sunkyung Cha, Tae-Eon Park, Kwangsu Kim, Simone Finizio, Jörg Raabe, Joonyeon Chang, Yan Zhou, Weisheng Zhao, Wang Kang, Hyunsu Ju, Seonghoon Woo

    Nature Electronics   3 ( 3 ) 148 - 155  2020.03  [Refereed]  [International journal]  [International coauthorship]

    DOI

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    440
    Citation
    (Scopus)

  • Direct imaging of an inhomogeneous electric current distribution using the trajectory of magnetic half-skyrmions

    Senfu Zhang, Xichao Zhang, Junwei Zhang, Arnab Ganguly, Jing Xia, Yan Wen, Qiang Zhang, Guoqiang Yu, Zhipeng Hou, Wenhong Wang, Yong Peng, Gang Xiao, Aurelien Manchon, Jürgen Kosel, Yan Zhou, Xi-Xiang Zhang

    Science Advances   6 ( 6 )  2020.02

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    23
    Citation
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  • A ferromagnetic skyrmion-based nano-oscillator with modified profile of Dzyaloshinskii-Moriya interaction

    J.H. Guo, J. Xia, X.C. Zhang, Philip W.T. Pong, Y.M. Wu, H. Chen, W.S. Zhao, Y. Zhou

    Journal of Magnetism and Magnetic Materials   496   165912 - 165912  2020.02

    DOI

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    31
    Citation
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  • Current-Induced Dynamics and Chaos of Antiferromagnetic Bimerons

    Laichuan Shen, Jing Xia, Xichao Zhang, Motohiko Ezawa, Oleg A. Tretiakov, Xiaoxi Liu, Guoping Zhao, Yan Zhou

    Physical Review Letters    2020.01

    DOI

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    105
    Citation
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  • A Comparative Cross-layer Study on Racetrack Memories

    Wang Kang, Bi Wu, Xing Chen, Daoqian Zhu, Zhaohao Wang, Xichao Zhang, Yan Zhou, Youguang Zhang, Weisheng Zhao

    ACM Journal on Emerging Technologies in Computing Systems   16 ( 1 ) 1 - 17  2019.10

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    21
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  • Dynamics of an antiferromagnetic skyrmion in a racetrack with a defect

    Xue Liang, Guoping Zhao, Laichuan Shen, Jing Xia, Li Zhao, Xichao Zhang, Yan Zhou

    Physical Review B   100 ( 14 )  2019.10

    DOI

  • Dynamics of antiskyrmions induced by the voltage-controlled magnetic anisotropy gradient

    Lei Qiu, Jing Xia, Youhua Feng, Laichuan Shen, Francois J. Morvan, Xichao Zhang, Xiaoxi Liu, Linhua Xie, Yan Zhou, Guoping Zhao

    Journal of Magnetism and Magnetic Materials     165922 - 165922  2019.09

    DOI

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    18
    Citation
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  • Magnetic Skyrmion Spectrum Under Voltage Excitation and its Linear Modulation

    Xing Chen, Wang Kang, Daoqian Zhu, Na Lei, Xichao Zhang, Yan Zhou, Youguang Zhang, Weisheng Zhao

    Physical Review Applied   12 ( 2 )  2019.08

    DOI

  • Nd-Fe-B films with perpendicular magnetic anisotropy and extremely large room temperature coercivity

    Chuang Ma, Jing Xia, Xichao Zhang, Yan Zhou, Akimitsu Morisako, S.N. Piramanayagam, Xiaoxi Liu

    Journal of Magnetism and Magnetic Materials   474   406 - 410  2019.03

    DOI

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    5
    Citation
    (Scopus)

  • An achiral ferromagnetic/chiral antiferromagnetic bilayer system leading to controllable size and density of skyrmions

    F. J. Morvan, H. B. Luo, H. X. Yang, X. Zhang, Y. Zhou, G. P. Zhao, W. X. Xia, J. P. Liu

    Scientific Reports   9 ( 1 )  2019.02

    DOI

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    11
    Citation
    (Scopus)

  • Spin torque nano-oscillators based on antiferromagnetic skyrmions

    Laichuan Shen, Jing Xia, Guoping Zhao, Xichao Zhang, Motohiko Ezawa, Oleg A. Tretiakov, Xiaoxi Liu, Yan Zhou

    Applied Physics Letters    2019.01

    DOI

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    132
    Citation
    (Scopus)

  • Voltage-Driven High-Speed Skyrmion Motion in a Skyrmion-Shift Device

    Yizheng Liu, Na Lei, Chengxiang Wang, Xichao Zhang, Wang Kang, Daoqian Zhu, Yan Zhou, Xiaoxi Liu, Youguang Zhang, Weisheng Zhao

    Physical Review Applied   11 ( 1 )  2019.01

    DOI

  • A skyrmion-based spin-torque nano-oscillator with enhanced edge

    Youhua Feng, Jing Xia, Lei Qiu, Xinran Cai, Laichuan Shen, Francois J. Morvan, Xichao Zhang, Yan Zhou, Guoping Zhao

    Journal of Magnetism and Magnetic Materials   491   165610 - 165610  2019

    DOI

    Scopus

    42
    Citation
    (Scopus)

  • Current-driven dynamics and inhibition of the skyrmion Hall effect of ferrimagnetic skyrmions in GdFeCo films

    Seonghoon Woo, Kyung Mee Song, Xichao Zhang, Yan Zhou, Motohiko Ezawa, Xiaoxi Liu, S. Finizio, J. Raabe, Nyun Jong Lee, Sang-Il Kim, Seung-Young Park, Younghak Kim, Jae-Young Kim, Dongjoon Lee, OukJae Lee, Jun Woo Choi, Byoung-Chul Min, Hyun Cheol Koo, Joonyeon Chang

    Nature Communications   9 ( 1 )  2018.12

    　View Summary

    Magnetic skyrmions are swirling magnetic textures with novel characteristics suitable for future spintronic and topological applications. Recent studies confirmed the room-temperature stabilization of skyrmions in ultrathin ferromagnets. However, such ferromagnetic skyrmions show an undesirable topological effect, the skyrmion Hall effect, which leads to their current-driven motion towards device edges, where skyrmions could easily be annihilated by topographic defects. Recent theoretical studies have predicted enhanced current-driven behavior for antiferromagnetically exchange-coupled skyrmions. Here we present the stabilization of these skyrmions and their current-driven dynamics in ferrimagnetic GdFeCo films. By utilizing element-specific X-ray imaging, we find that the skyrmions in the Gd and FeCo sublayers are antiferromagnetically exchange-coupled. We further confirm that ferrimagnetic skyrmions can move at a velocity of similar to 50 m s(-1) with reduced skyrmion Hall angle, |theta(SkHE)| similar to 20 degrees. Our findings open the door to ferrimagnetic and antiferromagnetic skyrmionics while providing key experimental evidences of recent theoretical studies.

    DOI

    Scopus

    332
    Citation
    (Scopus)

  • Dynamics of the antiferromagnetic skyrmion induced by a magnetic anisotropy gradient

    Laichuan Shen, Jing Xia, Guoping Zhao, Xichao Zhang, Motohiko Ezawa, Oleg A. Tretiakov, Xiaoxi Liu, Yan Zhou

    Physical Review B   98 ( 13 )  2018.10

    DOI

  • Complementary Skyrmion Racetrack Memory Enables Voltage-Controlled Local Data Update Functionality

    Xing Chen, Wang Kang, Daoqian Zhu, Xichao Zhang, Na Lei, Youguang Zhang, Yan Zhou, Weisheng Zhao

    IEEE Transactions on Electron Devices     1 - 7  2018.10

    DOI

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    7
    Citation
    (Scopus)

  • Strain-controlled skyrmion creation and propagation in ferroelectric/ferromagnetic hybrid wires

    Zhi Li, Youguang Zhang, Yangqi Huang, Chengxiang Wang, Xichao Zhang, Yan Liu, Yan Zhou, Wang Kang, Shradha Chandrashekhar Koli, Na Lei

    Journal of Magnetism and Magnetic Materials   455   19 - 24  2018.06

    DOI

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    44
    Citation
    (Scopus)

  • Controllable transport of a skyrmion in a ferromagnetic narrow channel with voltage-controlled magnetic anisotropy

    Junlin Wang, Jing Xia, Xichao Zhang, G P Zhao, Lei Ye, Jing Wu, Yongbing Xu, Weisheng Zhao, Zhigang Zou, Yan Zhou

    Journal of Physics D: Applied Physics   51 ( 20 ) 205002 - 205002  2018.05

    DOI

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    20
    Citation
    (Scopus)

  • Dynamics of a magnetic skyrmionium driven by spin waves

    Sai Li, Jing Xia, Xichao Zhang, Motohiko Ezawa, Wang Kang, Xiaoxi Liu, Yan Zhou, Weisheng Zhao

    Applied Physics Letters   112 ( 14 )  2018.04

    　View Summary

    A magnetic skyrmionium is a skyrmion-like structure, but carries a zero net skyrmion number which can be used as a building block for non-volatile information processing devices. Here, we study the dynamics of a magnetic skyrmionium driven by propagating spin waves. It is found that the skyrmionium can be effectively driven into motion by spin waves showing a tiny skyrmion Hall effect, whose mobility is much better than that of the skyrmion at the same condition. We also show that the skyrmionium mobility depends on the nanotrack width and the damping coefficient and can be controlled by an external out-of-plane magnetic field. In addition, we demonstrate that the skyrmionium motion driven by spin waves is inertial. Our results indicate that the skyrmionium is a promising building block for building spin-wave spintronic devices. Published by AIP Publishing.

    DOI

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    59
    Citation
    (Scopus)

  • Skyrmions in magnetic tunnel junctions

    Xueying Zhang, Wenlong Cai, Xichao Zhang, Zilu Wang, Zhi Li, Yu Zhang, Kaihua Cao, Na Lei, Wang Kang, Yue Zhang, Haiming Yu, Yan Zhou, Weisheng Zhao

    ACS Applied Materials & Interfaces    2018.04

    DOI

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    72
    Citation
    (Scopus)

  • Vortical structures for nanomagnetic memory induced by dipole-dipole interaction in monolayer disks

    Zhaosen Liu, Orion Ciftja, Xichao Zhang, Yan Zhou, Hou Ian

    Superlattices and Microstructures    2018.03

    DOI

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    6
    Citation
    (Scopus)

  • Dynamics of Magnetic Skyrmion Clusters Driven by Spin-Polarized Current With a Spatially Varied Polarization

    Wenjing Jiang, Jing Xia, Xichao Zhang, Yifan Song, Chuang Ma, Hans Fangohr, Guoping Zhao, Xiaoxi Liu, Weisheng Zhao, Yan Zhou

    IEEE Magnetics Letters   9   1 - 5  2018

    DOI

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    10
    Citation
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  • Skyrmions-based magnetic racetrack memory

    Liang Xue, Zhao Li, Qiu Lei, Li Shuang, Ding Li-Hong, Feng You-Hua, Zhang Xi-Chao, Zhou Yan, Zhao Guo-Ping

    Acta Physica Sinica   67 ( 13 ) 137510 - 137510  2018

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    10
    Citation
    (Scopus)

  • A compact skyrmionic leaky-integrate-fire spiking neuron device

    Xing Chen, Kang Wang, Daoqian Zhu, Xichao Zhang, Na Lei, Youguang Zhang, Yan Zhou, Weisheng Zhao

    Nanoscale    2018

    DOI

    Scopus

    102
    Citation
    (Scopus)

  • Overview of magnetic skyrmion-based devices and applications

    Xia Jing, Han Zong-Yi, Song Yi-Fan, Jiang Wen-Jing, Lin Liu-Rong, Zhang Xi-Chao, Liu Xiao-Xi, Zhou Yan

    Acta Physica Sinica   67 ( 13 ) 137505 - 137505  2018

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    7
    Citation
    (Scopus)

  • Skyrmion dynamics in width-varying nanotracks and implications for skyrmionic applications

    Xing Chen, Wang Kang, Daoqian Zhu, Xichao Zhang, Na Lei, Youguang Zhang, Yan Zhou, Weisheng Zhao

    Applied Physics Letters   111 ( 20 ) 202406 - 202406  2017.11

    DOI

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    34
    Citation
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  • A microwave field-driven transistor-like skyrmionic device with the microwave current-assisted skyrmion creation

    Jing Xia, Yangqi Huang, Xichao Zhang, Wang Kang, Chentian Zheng, Xiaoxi Liu, Weisheng Zhao, Yan Zhou

    Journal of Applied Physics   122 ( 15 ) 153901 - 153901  2017.10

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    29
    Citation
    (Scopus)

  • Magnetic domain wall engineering in a nanoscale permalloy junction

    Junlin Wang, Xichao Zhang, Xianyang Lu, Jason Zhang, Yu Yan, Hua Ling, Jing Wu, Yan Zhou, Yongbing Xu

    Applied Physics Letters   111 ( 7 ) 072401 - 072401  2017.08

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    20
    Citation
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  • Magnetic skyrmion-based artificial neuron device

    Sai Li, Wang Kang, Yangqi Huang, Xichao Zhang, Yan Zhou, Weisheng Zhao

    Nanotechnology   28 ( 31 )  2017.07

    DOI

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    186
    Citation
    (Scopus)

  • Creation, transport and detection of imprinted magnetic solitons stabilized by spin-polarized current

    R.P. Loreto, W.A. Moura-Melo, A.R. Pereira, X. Zhang, Y. Zhou, M. Ezawa, C.I.L. Araujo

    Journal of Magnetism and Magnetic Materials    2017.04

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    19
    Citation
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  • An Improved Racetrack Structure for Transporting a Skyrmion

    P. Lai, G. P. Zhao, H. Tang, N. Ran, S. Q. Wu, J. Xia, X. Zhang, Y. Zhou

    Scientific Reports   7   45330 - 45330  2017.03

    DOI

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    105
    Citation
    (Scopus)

  • Magnetic skyrmion-based synaptic devices

    Yangqi Huang, Wang Kang, Xichao Zhang, Yan Zhou, Weisheng Zhao

    Nanotechnology    2017.02

    DOI

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    259
    Citation
    (Scopus)

  • The influence of the edge effect on the skyrmion generation in a magnetic nanotrack

    N. Ran, G. P. Zhao, H. Tang, L. C. Shen, P. Lai, J. Xia, X. Zhang, Y. Zhou

    AIP Advances   7 ( 2 ) 025105 - 025105  2017.02

    DOI

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    18
    Citation
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  • Skyrmion Racetrack Memory With Random Information Update/Deletion/Insertion

    Daoqian Zhu, Wang Kang, Sai Li, Yangqi Huang, Xichao Zhang, Yan Zhou, Weisheng Zhao

    IEEE Transactions on Electron Devices     1 - 9  2017

    DOI

  • Compact Modeling and Evaluation of Magnetic Skyrmion-Based Racetrack Memory

    Wang Kang, Chentian Zheng, Yangqi Huang, Xichao Zhang, Weifeng Lv, Yan Zhou, Weisheng Zhao

    IEEE Transactions on Electron Devices     1 - 9  2017

    DOI

  • Skyrmion-Electronics: An Overview and Outlook

    Kang, Wang, Huang, Yangqi, Zhang, Xichao, Zhou, Yan, Zhao, Weisheng

    Proceedings of the IEEE   104 ( 10 )  2016

    DOI

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    325
    Citation
    (Scopus)

  • Voltage controlled magnetic skyrmion motion for racetrack memory

    Kang, Wang, Huang, Yangqi, Zheng, Chentian, Lv, Weifeng, Lei, Na, Zhang, Youguang, Zhang, Xichao, Zhou, Yan, Zhao, Weisheng

    Scientific Reports   6   23164 - 23164  2016

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    204
    Citation
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  • Spin-Cherenkov effect in a magnetic nanostrip with interfacial Dzyaloshinskii-Moriya interaction

    Xia, Jing, Zhang, Xichao, Yan, Ming, Zhao, Weisheng, Zhou, Yan

    Scientific Reports   6   25189 - 25189  2016

    DOI

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    12
    Citation
    (Scopus)

  • Hysteresis of misaligned hard-soft grains

    Wan, X. L., Zhao, G. P., Zhang, X. F., Xia, J., Zhang, Xichao, Morvan, F. J.

    Journal of Magnetism and Magnetic Materials   397  2016

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    4
    Citation
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  • Effect of exchange coupling on magnetic property in Sm-Co/α-Fe layered system

    Sang, C. X., Zhao, G. P., Xia, W. X., Wan, X. L., Morvan, F. J., Zhang, Xichao, Xie, L. H., Zhang, J., Du, J., Yan, A. R., Liu, P.

    Chinese Physics B   25 ( 3 ) 037501 - 037501  2016

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    10
    Citation
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  • Complementary skyrmion racetrack memory with voltage manipulation

    Kang, Wang, Zheng, Chentian, Huang, Yangqi, Zhang, Xichao, Zhou, Yan, Lv, Weifeng, Zhao, Weisheng

    IEEE Electron Device Letters   37 ( 7 ) 924 - 924  2016

    DOI

  • Skyrmion spin structure of exchange-coupled magnetic core-shell nanodisk

    Xia, Jing, Zhang, Xichao, Morvan, F. J., Zhao, G. P., Zhou, Yan

    IEEE Transactions on Magnetics   51 ( 11 )  2015

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    1
    Citation
    (Scopus)

  • Simulation of spin-torque diode microwave detectors

    Cao, Chong Long, Zhou, Yan, Zhang, Xichao, Wu, Yu Mao, Pong, Philip W.T.

    The European Physical Journal Applied Physics   69 ( 1 ) 10603 - 10603  2015

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    1
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  • Hysteresis loops, critical fields and energy products for exchange-spring hard/soft/hard trilayers

    Chen, B. Z., Yan, S., Ju, Y. Z., Zhao, G. P., Zhang, Xichao, Yue, M., Xia, J.

    Journal of Magnetics   20 ( 1 ) 31 - 31  2015

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    1
    Citation
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  • Micromagnetic analysis of the effect of the easy axis orientation on demagnetization process in Nd2Fe14B/α-Fe bilayers

    Xia, Jing, Zhang, Xichao, Zhao, G. P.

    Acta Physica Sinica   62   227502 - 227502  2013

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    6
    Citation
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  • 3D and 1D calculation of hysteresis loops and energy products for anisotropic nanocomposite films with perpendicular anisotropy

    Yuan, X. H., Zhao, G. P., Yue, M., Ye, L. N., Xia, J., Zhang, Xichao, Chang, J.

    Journal of Magnetism and Magnetic Materials   343   245 - 245  2013

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    31
    Citation
    (Scopus)

▼display all

Books and Other Publications

  • Magnetic Skyrmions and Their Applications

    Xichao Zhang, Jing Xia, Laichuan Shen, Motohiko Ezawa, Xiaoxi Liu, Yan Zhou( Part： Contributor, Chapter 13: Conventional Applications of Skyrmions)

    Elsevier  2021.06  [Refereed]

    DOI

  • Magnetic Skyrmions and Their Applications

    Xichao Zhang, Yan Zhou, Seonghoon Woo( Part： Contributor, Chapter 10: Skyrmions in ferrimagnets)

    Elsevier  2021.06  [Refereed]

    DOI

  • Skyrmions: Topological Structures, Properties, and Applications

    Xichao Zhang, Jing Xia, Guoping Zhao, Hans Fangohr, Motohiko Ezawa, Yan Zhou( Part： Contributor, Chapter 12: Racetrack-Type Applications of Magnetic Skyrmions)

    CRC Press  2016.12  [Refereed]

    DOI

  • Chirality, magnetism and magnetoelectricity: separate phenomena and Joint effects in metamaterial structures

    Laichuan Shen, Xue Liang, Jing Xia, Xichao Zhang, Motohiko Ezawa, Oleg A. Tretiakov, Yan Zhou( Part： Contributor, Chapter 16: Antiferromagnetic Skyrmions and Bimerons)

    Springer  2021.03 ISBN: 9783030628437  [Refereed]

    DOI

  • Skyrmions: Topological Structures, Properties, and Applications

    Guoping Zhao, Nian Ran, Ping Lai, François Jacques Morvan, Jing Xia, Xichao Zhang, Yan Zhou( Part： Contributor, Chapter 14: Skyrmions in Other Condensed Matter Systems)

    CRC Press  2016.12  [Refereed]

    DOI

Presentations

  • Dynamics of topological spin textures

    Xichao Zhang  [Invited]

    The International Conference on New Frontiers in Advanced Magnetism (NFAM-2024)  (Sapporo)  Hokkaido University

    Presentation date： 2024.08

    Event date：
    2024.08
    　
    　

  • Topological Spin Textures in Frustrated Magnetic Systems

    Xichao Zhang  [Invited]

    EEMD 2022 

    Presentation date： 2022.11

  • Frustrated magnetic skyrmions : from two dimensions to three dimensions

    Xichao Zhang[International coauthorship]

    The 46th Annual Conference on Magnetics in Japan 

    Presentation date： 2022.09

    Event date：
    2022.09
    　
    　

  • Frustrated Skyrmions and Bimerons

    Xichao Zhang  [Invited]

    The IEEE Around-the-Clock Around-the-Globe Magnetics Conference 2022 

    Presentation date： 2022.08

    Event date：
    2022.08
    　
    　

    　View Summary

    Skyrmions and bimerons are typical topological spin textures that can be stabilized in frustrated magnetic systems with competing exchange interactions [1]. They have multiple degrees of freedom, which could be manipulated by external driving forces and thus, may lead to novel applications, such as the helicity-based information processing in nanoscale devices. Therefore, it is important to understand the fundamental physical properties of frustrated skyrmions and bimerons, and to explore their potential applications.In this talk, I will first briefly introduce topological spin textures in magnetic systems [2]. I will then talk about the static and dynamic properties of isolated skyrmions and bimerons in a magnetic monolayer with frustrated exchange interactions [3]. I will focus on the discussion of the dynamic behaviors of isolated skyrmions and bimerons driven by spin torques, including linear motion, elliptical motion, and rotation. Besides, I will discuss the current-induced dynamics of a three-dimensional skyrmion string in a frustrated multilayer system [4]. Finally, at the end of the talk, I will share some views on possible future directions for the study of topological spin textures, which are not limited to the frustrated magnetic systems.

  • Configurable Pixelated Skyrmions on Nanoscale Grids

    Xichao Zhang[International coauthorship]

    The 2022 Joint MMM-INTERMAG Conference 

    Presentation date： 2022.01

    Event date：
    2022.01
    　
    　

  • Configurable pixelated skyrmions on nanoscale grids

    Xichao Zhang

    The 45th Annual Conference on Magnetics in Japan 

    Presentation date： 2021.08

    Event date：
    2021.08
    -
    2021.09

  • Frustrated magnetic skyrmions and bimerons

    Xichao Zhang

    The 2021 IEEE International Magnetics Conference (INTERMAG2021) 

    Presentation date： 2021.04

    Event date：
    2021.04
    　
    　

  • Frustrated magnetic skyrmions and bimerons

    Xichao Zhang  [Invited]

    SKYMAG 2021 

    Presentation date： 2021.04

    Event date：
    2021.03
    -
    2021.04

  • Static structures and dynamics of frustrated bimerons

    Xichao Zhang

    The 44th Annual Conference on Magnetics in Japan 

    Presentation date： 2020.12

    Event date：
    2020.12
    　
    　

  • Frustrated magnetic skyrmions in a monolayer thin film

    Xichao Zhang  [Invited]

    The 19th IEEE International Conference on Nanotechnology (IEEENANO2019) 

    Presentation date： 2019.07

    Event date：
    2019.07
    　
    　

  • Dynamics of skyrmions in a frustrated magnetic film driven by spin current

    Xichao Zhang

    The 79th JSAP Autumn Meeting 

    Presentation date： 2018.09

    Event date：
    2018.09
    　
    　

  • Current-induced skyrmion dynamics in a frustrated magnetic film

    Xichao Zhang

    The 2018 IEEE International Magnetics Conference (INTERMAG2018) 

    Presentation date： 2018.04

    Event date：
    2018.04
    　
    　

  • Synthetic antiferromagnetic skyrmions

    Xichao Zhang  [Invited]

    Tsinghua University, Department of Physics

    Presentation date： 2016.12

  • Configurable Pixelated Skyrmions on Nanoscale Grids

    Xichao Zhang[International coauthorship]

    The 24th International Colloquium on Magnetic Films and Surfaces (ICMFS-2022) 

    Presentation date： 2022.07

    Event date：
    2022.07
    　
    　

  • Topological spin textures in frustrated magnetic systems

    Xichao Zhang  [Invited]

    South China Normal University, South China Academy of Advanced Optoelectronics

    Presentation date： 2020.07

  • Topological spin textures in frustrated magnetic systems

    Xichao Zhang  [Invited]

    Sichuan Normal University, College of Physics and Electronic Engineering

    Presentation date： 2020.07

  • Magnetic skyrmions in novel materials and nanostructures

    Xichao Zhang  [Invited]

    The Chinese Academy of Sciences, High Magnetic Field Laboratory

    Presentation date： 2019.12

  • Magnetic skyrmions in novel materials and nanostructures

    Xichao Zhang  [Invited]

    Anhui University, Institutes of Physical Science and Information Technology

    Presentation date： 2019.12

  • Magnetic skyrmions in novel materials and nanostructures

    Xichao Zhang  [Invited]

    Sichuan Normal University, School of Physics and Electronic Engineering

    Presentation date： 2019.07

  • Frustrated magnetic skyrmions in monolayer and bilayer thin films

    Xichao Zhang  [Invited]

    UESTC Spintronics Mini Workshop 2019 

    Presentation date： 2019.06

    Event date：
    2019.06
    　
    　

  • Magnetic skyrmions in nanostructures and their applications

    Xichao Zhang  [Invited]

    South China Normal University, South China Academy of Advanced Optoelectronics

    Presentation date： 2018.11

  • Magnetic skyrmions in nanostructures and their applications

    Xichao Zhang  [Invited]

    Sichuan Normal University, School of Physics and Electronic Engineering

    Presentation date： 2018.10

  • Magnetic skyrmion Hall effect and methods for eliminating skyrmion Hall effect

    Xichao Zhang  [Invited]

    The Chinese Physical Society 2017 Fall Meeting 

    Presentation date： 2017.09

    Event date：
    2017.09
    　
    　

  • Magnetic skyrmion logic gates

    Xichao Zhang

    The 28th Magnetic Recording Conference (TMRC2017) 

    Presentation date： 2017.08

    Event date：
    2017.08
    　
    　

  • Magnetic skyrmion logic gates

    Xichao Zhang

    UESTC Spintronics Mini Workshop 2017 

    Presentation date： 2017.05

    Event date：
    2017.05
    　
    　

  • Synthetic antiferromagnetic skyrmions

    Xichao Zhang  [Invited]

    The 10th International Conference on Computational Physics (ICCP10) 

    Presentation date： 2017.01

    Event date：
    2017.01
    　
    　

  • Synthetic antiferromagnetic skyrmions

    Xichao Zhang  [Invited]

    Sichuan Normal University, School of Physics and Electronic Engineering

    Presentation date： 2016.12

  • Synthetic antiferromagnetic skyrmions

    Xichao Zhang  [Invited]

    The 2016 Forum on Novel Magnetic States, Materials and Devices 

    Presentation date： 2016.12

    Event date：
    2016.12
    　
    　

  • Synthetic antiferromagnetic skyrmions

    Xichao Zhang  [Invited]

    Beihang University, Spintronics Interdisciplinary Center

    Presentation date： 2016.12

  • Magnetic skyrmions in bilayer and multilayer nanotracks

    Xichao Zhang

    The 77th JSAP Autumn Meeting 

    Presentation date： 2016.09

    Event date：
    2016.09
    　
    　

  • All-magnetic control of magnetic skyrmions in a nanowire by spin waves

    Xichao Zhang

    The Gordon Research Conference (GRC) on Spin Dynamics in Nanostructures 

    Presentation date： 2015.07

    Event date：
    2015.07
    　
    　

  • Voltage-gated skyrmion transistor

    Xichao Zhang

    The 2015 IEEE International Magnetics Conference (INTERMAG2015) 

    Presentation date： 2015.05

    Event date：
    2015.05
    　
    　

  • All-magnetic control of magnetic skyrmions in a nanowire by spin waves

    Xichao Zhang

    The 9th International Conference on Computational Physics (ICCP9) 

    Presentation date： 2015.01

    Event date：
    2015.01
    　
    　

  • All-magnetic control of magnetic skyrmions in a nanowire by spin waves

    Xichao Zhang

    International Workshop on Simulation and Modeling of Emerging Electronics  The University of Hong Kong

    Presentation date： 2014.12

    Event date：
    2014.12
    　
    　

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Research Projects

  • Memory, Logic Computing, and Neural Networks Based on Topological Spin Textures

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows

    Project Year :

    2020.11
    -
    2023.03
     

Misc

  • Editorial: Generation, detection and manipulation of skyrmions in magnetic nanostructures

    H. Y. Yuan, X. Zhang, C. J. O. Reichhardt

    Frontiers in Physics   10 ( 964975 )  2022.08  [Refereed]  [Invited]  [International journal]  [International coauthorship]

    Article, review, commentary, editorial, etc. (scientific journal)  

    DOI

  • Topological Spin Textures and Their Applications

    Israa Medlej, Xichao Zhang, Roberto Zivieri

    Magnetism   1 ( 1 ) 58 - 59  2021.12  [Invited]  [International journal]  [International coauthorship]

    Article, review, commentary, editorial, etc. (scientific journal)  

    　View Summary

    Topological spin textures have been an extremely hot topic since their first experimental observation in 2009 [...]

    DOI

 

Academic Activities

  • Guest Editor

    Materials Today Quantum (ISSN: 2950-2578)  

    2024.02
    -
    Now

    　View Summary

    【論文募集】

    MATERIALS TODAY QUANTUM誌で特集号を企画しています。
    みなさんからの投稿を大歓迎します。

    特集のテーマ：スピントロニクスとトポロジカル磁性
    ゲストエディタ：Yan Zhou (CUHKSZ), Johan Åkerman (東北大・ヨーテボリ大), Xichao Zhang (早大)
    投稿締切予定：２０２４年８月１日

    https://www.sciencedirect.com/journal/materials-today-quantum/about/call-for-papers

    CALL FOR PAPERS

    MATERIALS TODAY QUANTUM (ISSN: 2950-2578)
    Spintronics and Topological Magnetism
    https://www.sciencedirect.com/journal/materials-today-quantum/about/call-for-papers

    Guest Editors
    Yan Zhou (CUHKSZ), Johan Åkerman (Gothenburg/Tohoku), Xichao Zhang (Waseda)

    Submission Deadline: August 1, 2024

    All submissions on topics relevant to spintronics, magnetism, and topology are welcome!

  • Associate Editor

    Frontiers in Physics (ISSN: 2296-424X)  

    2023.09
    -
    Now

    　View Summary

    Your research is welcome. Submit your work here:
    https://www.frontiersin.org/journals/physics

  • Editorial Board Member

    Magnetism (ISSN: 2673-8724)  

    2021.06
    -
    Now

    　View Summary

    Your research is welcome. Submit your work here:
    https://www.mdpi.com/journal/magnetism

  • Guest Editor

    Journal of Magnetism and Magnetic Materials  

    2022.01
    -
    2022.11

  • Guest Editor

    Magnetism (ISSN: 2673-8724)  

    2021.06
    -
    2022.09

  • Topic Editor

    Frontiers in Physics (ISSN: 2296-424X)  

    2020.12
    -
    2022.08

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