Nano-Magnetism Lab.

Welcome

We study the magnetism and magnetic dynamics in restricted symmetry systems.
The restricted symmetry systems include spatially confined system (nano structure), low dimensional systems where limited translational symmetry applies, systems without inversions symmetry including asymmetric exchange interaction(Dzyaloshinskii Moriya interaction), coupled systems with non-uniform magnetic moments, magnetic heterostructures, complex spin structures, and etc.
In the restricted symmetry systems, rich magnetic phenomena occur due to various enhanced interactions such as asymmetric exchange interaction, high order anisotropies, dipolar interaction.
The rich mangetic behaviors are affected by external field, electric current and temperature, which we also investigate the mechanism. And these effects are related with applications using spin current, or spintronics.
To do research, we use our own lab-built programs which uses Monte-Calro method, Lagevin dynamics, Landau Lifshitz dynamics and more.
Recently, as deep learning technology has developed, we are conducting research on magnetic materials using this technology.
We also work with experiment groups at Physics Department, Fudan University in China and SPLEEM group in LBNL, USA.

Members

• 원창연 Changyeon Won : Professor

• 윤한규 Han Gyu Yoon : PhD Candidate

• 박성민 Seong Min Park : Graduate Student

• 문태정 Tae Jung Moon : Graduate Student

• 유경훈 Gyung Hun Yu : Ungraduate Student

Publications

2013-Present

• Melting phenomena of self-organized magnetic structures investigated by variational autoencoder
  -HG Yoon, DB Lee, SM Park, JW Choi, HY Kwon, C Won , Computer Physics Communications (2024)

• Indexing Topological Numbers on Images by Transferring Chiral Magnetic Textures
  -SM Park, TJ Moon, HG Yoon, HY Kwon, C Won , Advanced Materials Technologies (2024)

• Topological magnetic structure generation using VAE-GAN hybrid model and discriminator-driven latent sampling
  -SM Park, HG Yoon, DB Lee, JW Choi, HY Kwon, C Won , Scientific reports (2023)

• Super-resolution of magnetic systems using deep learning
  -DB Lee, HG Yoon, SM Park, JW Choi, G Chen, HY Kwon, C Won , Scientific reports (2023)

• Spontaneous asymmetry of chiral magnetic domains within a magnetic field
  -Qian Li, Mengmeng Yang, Gong Chen, Han Gyu Yoon, Hee Young Kwon, Changyeon Won, Tianye Wang, Chanyong Hwang, Xixiang Zhang, Yizheng Wu, Andreas K Schmid, Ziqiang Qiu , Advanced Functional Materials (2022)

• Searching for the ground state of complex spin-ice systems using deep learning techniques
  -HY Kwon, HG Yoon, SM Park, DB Lee, D Shi, Y Z Wu, JW Choi, C Won , Scientific reports (2022)

• Shock-wave-like emission of spin waves induced by the interfacial Dzyaloshinskii-Moriya interaction
  -H Xia, H Chen, C Won, H Zhao, Y Wu , Journal of Magnetism and Magnetic Materials (2022)

• Optimization of physical quantities in the autoencoder latent space
  - SM Park, HG Yoon, DB Lee, JW Choi, HY Kwon, C Won , Scientific reports (2022)

• Reversible writing/deleting of magnetic skyrmions through hydrogen adsorption/desorption
  -G Chen, C Ophus,A Quintana, H Kwon, C Won, H Ding, Y Wu, AK Schmid, K Liu , Nature communications (2022)

• Interpolation and extrapolation between the magnetic chiral states using autoencoder
  - HG Yoon, C Lee, DB Lee, SM Park, JW Choi, HY Kwon, C Won , Computer Physics Communications (2022)

• Estimating the effective fields of spin configurations using a deep learning technique
  - DB Lee, HG Yoon, SM Park , JW Choi, HY Kwon, C Won , Scientific reports (2021)

• Chirality-induced zigzag domain wall in in-plane magnetized ultrathin films
  -G Chen, MC Robertson, H Kwon, C Won, AK Schmid, K Liu , Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films(2021)

• Multi-domain ferromagnetic resonance in magnetic van der Waals crystals CrI3 and CrBr3
  -X Shen, H Chen, Y Li, H Xia, F Zeng, J Xu, HY Kwon, Y Ji, C Won , Journal of Magnetism and Magnetic Materials (2021)

• Magnetic State Generation using Hamiltonian Guided Variational Autoencoder with Spin Structure Stabilization
  -HY Kwon, HG Yoon, SM Park, DB Lee, JW Choi, C Won , Advanced Science (2021)

• High-density Néel-type magnetic skyrmion phase stabilized at high temperature
  -HY Kwon, KM Song, J Jeong, AY Lee, SY Park, J Kim, C Won, BC Min , NPG Asia Materials (2021)

• Versatile Motion Control of a Magnetic Skyrmion Pair with Spin Transfer Torque
  -NJ Kim, SP Kang, C Lee, HG Yoon, HY Kwon, C Won , Journal of the Korean Physical Society (2020)

• Magnetic Hamiltonian parameter estimation using deep learning technique
  - HY Kwon, HG Yoon, C Lee, G Chen, K Liu, AK Schmid, YZ Wu, JW Choi, C Won , Science advances(2020)

• In-plane Néel wall chirality and orientation of interfacial Dzyaloshinskii-Moriya vector in magnetic films
  -MacCallum Robertson, Christopher J Agostino, Gong Chen, Sang Pyo Kang, Arantzazu Mascaraque, Enrique Garcia Michel, Changyeon Won, Yizheng Wu, Andreas K Schmid, Kai Liu , Physical review B (2020)

• Magnetic structures in the locally inverted interlayer coupling region of a bilayer magnetic system
  - C Lee, HY Kwon, NJ Kim, HG Yoon, C Song, DB Lee, JW Choi, YW Son, C Won , JMMM(2020)

• An innovative magnetic state generator using machine learning techniques
  -HY Kwon, NJ Kim, CK Lee, HG Yoon, JW Choi, C Won , Scientific reports (2019)

• Edge-soliton-meditated fast vortex core dynamic switching in a notched magnetic disk
  -YM Luo, TJ Zhou, ZH Qian, X Xiao, ZT Liu, C Zhou, C Won, YZ Wu , Journal of Magnetism and Magnetic Materials (2019)

• Searching magnetic states using an unsupervised machine learning algorithm with the Heisenberg
  -HY Kwon, NJ Kim, CK Lee, C Won , Physical Review B (2019)

• The spin structures of interlayer coupled magnetic films with opposite chirality
  -SP Kang, NJ Kim, HY Kwon, JW Choi, BC Min, C Won , Scientific reports (2018)

• Magnetization reversal in kagome artificial spin ice studied by first-order reversal curves
  -L Sun, C Zhou, JH Liang, T Xing, N Lei, P Murray, K Liu, C Won, YZ Wu , Physical Review B (2017)

• Field dependence of antiferromagnetic domain switching in epitaxial Fe/CoO/MgO (001) systems
  -Q Li, TP Ma, M Yang, L Sun, SY Huang, RW Li, C Won, ZQ Qiu, YZ Wu , Physical Review B (2017)

• Elastic moduli and Poisson's ratio of 2-dimensional magnetic skyrmion lattice
  - S. P. Kang, H. Y. Kwon, and C. Won , JAP (2017)

• Out-of-plane chiral domain wall spin-structures in ultrathin in-plane magnets
  -Gong Chen, Sang Pyo Kang, Colin Ophus, Alpha T. N’Diaye, Hee Young Kwon, Ryan T. Qiu, Changyeon Won, Kai Liu, Yizheng Wu & Andreas K. Schmid , Nature communications (2017)

• Antiferromagnetic proximity effect in epitaxial CoO/NiO/MgO(001) systems
  -Q. Li, J. H. Liang, Y. M. Luo, Z. Ding, T. Gu, Z. Hu, C. Y. Hua, H.-J. Lin, T. W. Pi, S. P. Kang, C. Won, Y. Z. Wu , Scientific Reports (2016)

• Effect of interlayer exchange coupling on magnetic chiral structures
  - S. P. Kang, H. Y. Kwon, H. S. Kim, J. H. Shim, and C. Won , JAP (2015)

• Unlocking Bloch-type chirality in ultrathin magnets through uniaxial strain
  -Gong Chen, Alpha T. N’Diaye, Sang Pyo Kang, Hee Young Kwon, Changyeon Won, Yizheng Wu, Z.Q. Qiu, Andreas K. Schmid, Nature Communications (2015)

• Magnetic vortex gyration affected by Dzyaloshinskii–Moriya interaction
  -Y. M. Luo, C. Zhou, C. Won , and Y. Z. Wu, JAP (2015)

• Multiple in-plane spin reorientation transitions in Fe/CoO bilayers grown on vicinal MgO(001)
  -Q. Li, T. Gu, J. Zhu, Z. Ding, J. X. Li, J. H. Liang, Y. M. Luo, Z. Hu,C. Y. Hua , H.-J. Lin, T. W. Pi, C. Won , and Y. Z. Wu, PRB (2015)

• Activation of antiferromagnetic domain switching in exchange-coupled Fe/CoO/MgO(001) systems
  -Q. Li, G. Chen, T. P. Ma, J. Zhu, A. T. N’Diaye, L. Sun, T. Gu, Y. Huo, J. H. Liang, R. W. Li, C. Won , H. F. Ding, Z. Q. Qiu, and Y. Z. Wu1, PRB(2015)

• Effects of Dzyaloshinskii–Moriya interaction on magnetic stripe domains
  - H. Y. Kwon, C. Won , JMMM(2014)

• Effect of Dzyaloshinskii–Moriya interaction on magnetic vortex
  -Y. M. Luo, C. Zhou, C. Won , Y. Z. Wu, AIP Advances (2014)

• Gyration eigenfrequencies of vertically coupled vortices in layered magnetic disks
  -Y. M. Luo, C. Zhou, C. Won , and Y. Z. Wu, JAP (2014)

• Strain-modulated antiferromagnetic spin orientation and exchange coupling in Fe/CoO(001)
  -J. Zhu, Q. Li, J. X. Li, Z. Ding, C. Y. Hua, M. J. Huang, H.-J. Lin, Z. Hu, C. Won , and Y. Z. Wu , JAP (2014)

• Antiferromagnetic spin reorientation transition in epitaxial NiO/CoO/MgO(001) systems
  -J. Zhu, Q. Li, J. X. Li, Z. Ding, J. H. Liang, X. Xiao, Y. M. Luo, C. Y. Hua, H.-J. Lin, T. W. Pi, Z. Hu, C. Won , and Y. Z. Wu, PRB (2014)

• Magnetic vortex generated by Dzyaloshinskii–Moriya interaction
  - H. Y. Kwon, S. P. Kang, Y. Z. Wu, and C. Won , JAP (2013)

• Ordered growth of magnetic helical structure under the Dzyaloshinskii–Moriya interaction
  - K.M. Bu , H.Y. Kwon , S.P. Kang , H.J. Kim , C. Won , JMMM (2013)

• Effect of In-plane Uniaxial Anisotropy on Self-organized Magnetic Structures Generated by the Dzyaloshinskii-Moriya interaction
  - S. W. Oh, H. Y. Kwon and C. Won , JKPS (2013)

• Novel Chiral Magnetic Domain Wall Structure in Fe/Ni/Cu(001) Films
  -G. Chen, J. Zhu, A. Quesada, J. Li, A. T. N’Diaye, Y. Huo, T. P. Ma, Y. Chen, H. Y. Kwon, C. Won, Z. Q. Qiu, A. K. Schmid, and Y. Z. Wu, PRL (2013)

• Tailoring the chirality of magnetic domain walls by interface engineering
  -Gong Chen, Tianping Ma, Alpha T. N’Diaye, Heeyoung Kwon, Changyeon Won , Yizheng Wu, and Andreas K. Schmid , Nature Communications (2013)

• Volume contribution of exchange-coupling-induced uniaxial anisotropy in Fe/CoO/MgO(001) system
  -J. Zhu, Q. Li, J. X. Li, Z. Ding, C. Won et al., JAP (2013)

• Three-dimensional mapping of the anisotropic magnetoresistance in Fe₃O₄ single crystal thin films
  -Z. Ding, J. X. Li, J. Zhu, T. P. Ma, C. Won et al., JAP (2013)