TY - JOUR
T1 - Generation of terahertz transients from Co2Fe0.4Mn0.6Si Heusler alloy/heavy-metal bilayers
AU - Heidtfeld, S.
AU - Adam, R.
AU - Kubota, T.
AU - Takanashi, K.
AU - Cao, D.
AU - Schmitz-Antoniak, C.
AU - Bürgler, D. E.
AU - Wang, F.
AU - Greb, C.
AU - Chen, G.
AU - Komissarov, I.
AU - Hardtdegen, H.
AU - Mikulics, M.
AU - Sobolewski, R.
AU - Suga, S.
AU - Schneider, C. M.
N1 - Funding Information:
The work at the Research Center Jülich was performed within JuSPARC (Jülich Short-pulse Particle Acceleration and Radiation Center) [11] , a strategy project funded by the Bundesministerium für Bildung und Forschung (Federal Ministry of Education and Science, Germany). Research in Rochester was funded in part by the National Science Foundation grant # 1842712 .
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021
Y1 - 2021
N2 - We generated pulses of electromagnetic radiation with a frequency content up to three terahertz (THz) by optical excitation of Co2Fe0.4Mn0.6Si Heusler alloy/heavy metal bilayers (CFMS/HM) using fs-laser pulses. We attribute the generation process to the conversion of a spin current, generated by the illumination with a fs-laser pulse, to a charge current via the inverse spin Hall effect. We compared the THz emission efficiency in CFMS/Pt and CFMS/Ta bilayers due to their high spin–orbit coupling of Pt and Ta. Surprisingly, our data reveal that CFMS/Pt shows substantially larger THz amplitudes compared to CFMS/Ta. Both bilayers exhibit a tunability of the THz amplitude by external magnetic field both at 300 K and 100 K. Ferromagnetic resonance measurements demonstrate that CFMS/Ta has a high effective spin mixing conductance, describing the efficiency of interfacial spin transport. We observe that the efficiency of the THz radiation cannot be solely described by the spin–orbit coupling strength and the spin diffusion length in the HM material plays an important role.
AB - We generated pulses of electromagnetic radiation with a frequency content up to three terahertz (THz) by optical excitation of Co2Fe0.4Mn0.6Si Heusler alloy/heavy metal bilayers (CFMS/HM) using fs-laser pulses. We attribute the generation process to the conversion of a spin current, generated by the illumination with a fs-laser pulse, to a charge current via the inverse spin Hall effect. We compared the THz emission efficiency in CFMS/Pt and CFMS/Ta bilayers due to their high spin–orbit coupling of Pt and Ta. Surprisingly, our data reveal that CFMS/Pt shows substantially larger THz amplitudes compared to CFMS/Ta. Both bilayers exhibit a tunability of the THz amplitude by external magnetic field both at 300 K and 100 K. Ferromagnetic resonance measurements demonstrate that CFMS/Ta has a high effective spin mixing conductance, describing the efficiency of interfacial spin transport. We observe that the efficiency of the THz radiation cannot be solely described by the spin–orbit coupling strength and the spin diffusion length in the HM material plays an important role.
KW - Ferromagnetic resonance
KW - Inverse spin hall effect
KW - Spin-to-charge conversion
KW - THz radiation
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U2 - 10.1016/j.jmmm.2021.168791
DO - 10.1016/j.jmmm.2021.168791
M3 - Article
AN - SCOPUS:85119397936
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
SN - 0304-8853
M1 - 168791
ER -