Saito Yuichi, Mikhaylovskiy Rostislav V
Department of Physics, Lancaster University, Bailrigg, Lancaster LA1 4YW, UK.
Faraday Discuss. 2022 Sep 15;237(0):381-388. doi: 10.1039/d2fd00035k.
Excitation with an ultrashort light pulse is arguably the only way to control spins in antiferromagnetic materials at both the nanoscale in space and ultrafast time scale. While recent experiments highlighted tantalising opportunities for spin switching and magnonics in antiferromagnets, the theoretical description of antiferromagnetic spin dynamics driven by strongly localised and ultrashort excitation is in its infancy. Here we report a theoretical model describing the nonlocal and nonlinear spin response to the excitation by light. We show that strongly localised ultrafast excitation can drive spin switching, which propagates in space and acts as a source of spin waves. Our theoretical formalism is readily available to describe current and future ultrafast spectroscopy experiments in antiferromagnets.
用超短光脉冲进行激发可以说是在空间纳米尺度和超快时间尺度上控制反铁磁材料中自旋的唯一方法。虽然最近的实验突出了反铁磁体中自旋切换和磁子学的诱人机会，但由强局域化和超短激发驱动的反铁磁自旋动力学的理论描述仍处于起步阶段。在此，我们报告了一个描述光激发的非局部和非线性自旋响应的理论模型。我们表明，强局域化的超快激发可以驱动自旋切换，其在空间中传播并充当自旋波源。我们的理论形式很容易用于描述当前和未来反铁磁体中的超快光谱实验。
