铁铑中反铁磁-铁磁相变的超快动力学

Ultrafast kinetics of the antiferromagnetic-ferromagnetic phase transition in FeRh.

作者信息

Li G, Medapalli R, Mentink J H, Mikhaylovskiy R V, Blank T G H, Patel S K K, Zvezdin A K, Rasing Th, Fullerton E E, Kimel A V

机构信息

Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, Nijmegen, The Netherlands.

Center for Memory and Recording Research, University of California, San Diego, La Jolla, San Diego, CA, 92093-0401, USA.

出版信息

Nat Commun. 2022 May 30;13(1):2998. doi: 10.1038/s41467-022-30591-2.

DOI:10.1038/s41467-022-30591-2

PMID:35637202

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9151753/

Abstract

Understanding how fast short-range interactions build up long-range order is one of the most intriguing topics in condensed matter physics. FeRh is a test specimen for studying this problem in magnetism, where the microscopic spin-spin exchange interaction is ultimately responsible for either ferro- or antiferromagnetic macroscopic order. Femtosecond laser excitation can induce ferromagnetism in antiferromagnetic FeRh, but the mechanism and dynamics of this transition are topics of intense debates. Employing double-pump THz emission spectroscopy has enabled us to dramatically increase the temporal detection window of THz emission probes of transient states without sacrificing any loss of resolution or sensitivity. It allows us to study the kinetics of emergent ferromagnetism from the femtosecond up to the nanosecond timescales in FeRh/Pt bilayers. Our results strongly suggest a latency period between the initial pump-excitation and the emission of THz radiation by ferromagnetic nuclei.

摘要

理解短程相互作用如何快速建立长程有序是凝聚态物理中最引人入胜的课题之一。FeRh是研究磁性领域这一问题的测试样本，其中微观自旋-自旋交换相互作用最终决定了铁磁或反铁磁宏观有序状态。飞秒激光激发可在反铁磁FeRh中诱导出铁磁性，但这种转变的机制和动力学仍是激烈争论的话题。采用双泵浦太赫兹发射光谱技术使我们能够在不损失任何分辨率或灵敏度的情况下，大幅增加对瞬态太赫兹发射探针的时间检测窗口。这使我们能够研究FeRh/Pt双层膜中从飞秒到纳秒时间尺度上新兴铁磁性的动力学。我们的结果有力地表明，在初始泵浦激发与铁磁核发射太赫兹辐射之间存在一个延迟期。