[NCTS Seminar] Ab Initio Materials Simulations for Noncollinear Magnetic Systems

• Event Date: 2025-12-09
• Chen, Jhan Yu 陳詹喻
• Condensed Matter and Materials Physics Computational quantum materials
• Speaker: Prof. Hsiao-Yi Chen (Tohoku University)  /  Host: Prof. Guang-Yu Guo & Dr. Yang-hao Chan
  Place: NCTS Physics Seminar Room 307, 3F, Cosmology Hall, NTU

Title: [NCTS Seminar] Ab Initio Materials Simulations for Noncollinear Magnetic Systems
Speaker: Prof. Hsiao-Yi Chen (Tohoku University)
Time: 2025/12/9 (Tue.) 10:20
Place: NCTS Physics Seminar Room 307, 3F, Cosmology Hall, NTU
 

Abstract

Noncollinear magnetic materials, characterized by spins aligned along different axes in the ground state, have been recognized as promising platforms for next-generation spintronic applications. Their intrinsic noncollinearity gives rise to complex spin textures such as skyrmions and spin helices, which are topologically distinct from collinear configurations, making them robust even at room temperatures. They combine advantages of both ferromagnets and antiferromagnets, with faster magnetic dynamics and free from stray-field effects, while simultaneously supporting spinpolarized currents and hosting exotic transport phenomena, including the anomalous Hall and Nernst effects. In addition, noncoplanar spin structures can induce the topological Hall effect in the absence of spin-orbit coupling, which is typically required for the conventional anomalous Hall effect.

However, in contrast to the advancement of experiment techniques in generating and controlling the noncollinear spin configurations, the lack of a theoretical method for simulating and predicting their physical properties has hindered the exploration for candidate materials and the further realization in spintronic devices. Targeting this gap, we developed an efficient first-principles scheme based on the density functional theory, which enables parameter-free simulation of groundstate electronic structures, response behaviors and collective excitations. Beside its numerically accurate predictions, the formalism further provides microscopic insight into the interplay among local spin, transport carriers, and external driving forces. In this talk, we will introduce the theoretical setup of the formalism and its applications in predicting phenomena arising exclusively from noncollinear spin textures [1,2].

Reference

[1] H.-Y. Chen, T. Nomoto, M. Hirschberger, and R. Arita, Phys. Rev. X 15 (1), 011054
[2] H.-Y. Chen, R. Arita, and Y. Nomura, arXiv: 2510.14405