太赫兹光磁学：反铁磁 FeBO_{3}中太赫兹波激发 GHz 自旋波的非线性过程。

Terahertz Optomagnetism: Nonlinear THz Excitation of GHz Spin Waves in Antiferromagnetic FeBO_{3}.

机构信息

Radboud University, Institute for Molecules and Materials, 6525 AJ Nijmegen, The Netherlands.

MIREA-Russian Technological University, Moscow 119454, Russia.

出版信息

Phys Rev Lett. 2019 Oct 11;123(15):157202. doi: 10.1103/PhysRevLett.123.157202.

DOI:10.1103/PhysRevLett.123.157202

PMID:31702317

Abstract

A nearly single cycle intense terahertz (THz) pulse with peak electric and magnetic fields of 0.5 MV/cm and 0.16 T, respectively, excites both modes of spin resonances in the weak antiferromagnet FeBO_{3}. The high frequency quasiantiferromagnetic mode is excited resonantly and its amplitude scales linearly with the strength of the THz magnetic field, whereas the low frequency quasiferromagnetic mode is excited via a nonlinear mechanism that scales quadratically with the strength of the THz electric field and can be regarded as a THz inverse Cotton-Mouton effect. THz optomagnetism is shown to be more energy efficient than similar effects reported previously for the near-infrared spectral range.

摘要

一个近单周期强太赫兹（THz）脉冲，其峰值电场和磁场分别为 0.5MV/cm 和 0.16T，分别激发弱反铁磁体 FeBO3 中的两种自旋共振模式。高频准反铁磁模式通过共振被激发，其幅度与 THz 磁场强度呈线性关系，而低频类铁磁模式则通过与 THz 电场强度呈二次关系的非线性机制被激发，可以视为 THz 逆科顿-莫顿效应。THz 光磁效应比以前报道的近红外光谱范围内的类似效应更节能。