[9a-E207-1~9] 10.4 Spintronics in semiconductor, topological material, superconductor, and multiferroics

9:15 AM - 9:30 AM JST(12:15 AM - 12:30 AM UTC)English Presentation

[9a-E207-2] Efficient Terahertz Emission from Topological Kagome Magnet Fe₃Sn₂

〇(P)Anulekha De¹, Soma Miki¹, Zaizhou Jin^1,3, Deepak Kumar¹, Edouard Lesne², Koki Nukui^1,3, Kyung-Hun Ko^1,4, Claudia Felser², Atsufumi Hirohata^4,2, Shigemi Mizukami^1,4 (1.AIMR, Tohoku Univ., 2.MPI Dresden, Germany, 3.GS Eng. Tohoku Univ., 4.CSIS, Tohoku Univ.)

Keywords:

THz emission,Topological kagome magnet

Topological kagome magnets have attracted considerable attention owing to their non-trivial electronic structure featuring Dirac fermions, flat bands and large Berry curvature, which lead to large anomalous Hall effects (AHE), strong spin–orbit-coupling (SOC) and efficient spin–charge-conversion playing important role in THz generation after femtosecond laser excitation. While the transport properties [1–3] and spin dynamics [4,5] of Fe₃Sn₂ have been studied, THz emission from this material has not yet been reported. Fe₃Sn₂ hosts a bilayer kagome lattice of Fe atoms separated by Sn layers. We observe efficient THz emission from epitaxial Fe₃Sn₂ thin films (Pt and Si capping) grown on SrTiO₃(111) substrate with Ru seed layer. We perform the measurements in reflection geometry using a home-built THz emission spectroscopy setup [6,7] driven by a Ti:Sapphire amplified laser. The THz signal reverses polarity with magnetic field reversal, confirming its magnetic origin and reversal of the underlying transient current upon magnetization reversal. Notably, Pt- and Si-capped samples exhibit distinct THz emission characteristics, indicating different generation mechanisms. These findings establish topological kagome magnets as promising materials for efficient THz emitters and highlight the influence of topological electronic structure in governing ultrafast spin–charge conversion. This work is supported by JSPS KAKENHI (24K21234, 26H02126), MEXT X-NICS (JPJ011438), and JST ASPIRE (JPMJAP2409).
References:
[1] L. Ye. et al., Nature 555, 638 (2018)
[2] H. Zhang et al., Phys. Rev. B 103, L201101 (2021)
[3] T. Chen et al, Sci. Adv. 8, eabk1480 (2022)
[4] I. Lyalin et al., Nano Lett. 21, 6975 (2021)
[5] C. Lee et al., PNAS, 120, e2220589120 (2023)
[6] Y. Sasaki et. al., Appl. Phys. Lett. 111, 102401 (2017)
[7] R. Mandal et al. NPG Asia Mater. 16, 30 (2024)