Year: 2025
Type: article
Abstract: -wave ferromagnets (FMs) and antiferromagnets (AFMs), while they produce distinct momentum-space nodes in altermagnets (AMs). Both drive anisotropic femtosecond magnetization dynamics, but this link remains little explored. Here, we investigate laser-driven ultrafast spin dynamics in FMs, AFMs, and AMs with varying polarization angles using time-dependent density functional theory. We demonstrated, in FMs and AFMs, that laser polarization controls the amplitude of anisotropic yet symmetric demagnetization. In contrast, AMs─featuring spin nodal structures─exhibit sublattice-asymmetric demagnetization that is highly sensitive to laser incidence. This behavior arises from the anisotropy of the Fermi surface and band dispersion, which governs optical-induced intersite spin transfer (OISTR). We proposed a unified framework using the band-path-resolved local density of states to understand anisotropic OISTR and its impact on spin dynamics. Our results establish a direct connection between polarization-dependent ultrafast spin responses and the anisotropic electronic structure of materials.
Source: Nano Letters
Authors: Zhaobo Zhou, Junjie He
Institution: Charles University
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Award: G6620679071
OpenAlex ID: W4415475801