Ultrafast optical observation of spin-pumping induced dynamic exchange coupling in ferromagnetic semiconductor/metal bilayer

• Published in: arXiv.org
• Main Authors: Liu, X, Liu, P, Yuan, H C, Shi, J Y, Wang, H L, Nie, S H, Jin, F, Zheng, Z, Yu, X Z, Zhao, J H, Zhao, H B, Lüpke, G
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 07.05.2022
• Subjects: Angular momentum; Bilayers; Coupling; Damping; Exchanging; Ferromagnetic resonance; Ferromagnetism; Kerr magnetooptical effect; Momentum transfer; Optical pumping; Physics - Applied Physics; Physics - Materials Science; Physics - Strongly Correlated Electrons; Spin dynamics; Temperature dependence
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2203.03225

Spin angular momentum transfer in magnetic bilayers offers the possibility of ultrafast and low-loss operation for next-generation spintronic devices. We report the field- and temperature- dependent measurements on the magnetization precessions in Co\(_2\)FeAl/(Ga,Mn)As by time-resolved magneto-optical Kerr effect (TRMOKE). Analysis of the effective Gilbert damping and phase shift indicates a clear signature of an enhanced dynamic exchange coupling between the two ferromagnetic (FM) layers due to the reinforced spin pumping at resonance. The temperature dependence of the dynamic exchange-coupling reveals a primary contribution from the ferromagnetism in (Ga,Mn)As.