Excitation and detection of coherent sub-terahertz magnons in ferromagnetic and antiferromagnetic heterostructures  

作　　者：Shihao Zhuang Jia-Mian Hu 

机构地区：[1]Department of Materials Science and Engineering,University of Wisconsin-Madison,Madison,WI,53706,USA

出　　处：《npj Computational Materials》2022年第1期1606-1614,共9页计算材料学（英文）

基　　金：J.-M.H.acknowledges support from the NSF award CBET-2006028 and the Accelerator Program from the Wisconsin Alumni Research Foundation;The simulations were performed using Bridges at the Pittsburgh Supercomputing Center through allocation TG-DMR180076,which is part of the Extreme Science and Engineering Discovery Environment(XSEDE)and supported by NSF grant ACI-1548562.

摘　　要：Excitation of coherent high-frequency magnons(quanta of spin waves)is critical to the development of high-speed magnonic devices.Here we computationally demonstrate the excitation of coherent sub-terahertz(THz)magnons in ferromagnetic(FM)and antiferromagnetic(AFM)thin films by a photoinduced picosecond acoustic pulse.Analytical calculations are also performed to reveal the magnon excitation mechanism.Through spin pumping and spin-charge conversion,these magnons can inject sub-THz charge current into an adjacent heavy-metal film which in turn emits electromagnetic(EM)waves.Using a dynamical phase-field model that considers the coupled dynamics of acoustic waves,spin waves,and EM waves,we show that the emitted EM wave retains the spectral information of all the sub-THz magnon modes and has a sufficiently large amplitude for near-field detection.These predictions indicate that the excitation and detection of sub-THz magnons can be realized in rationally designed FM or AFM thin-film heterostructures via ultrafast optical-pump THz-emission-probe spectroscopy.

关 键 词：PUMPING pump COHERENT 

分 类 号：TN2[电子电信—物理电子学]