Abstract-Photoinduced terahertz radiation and negative conductivity dynamics in Heusler alloy Co2MnSn film

Shunnong Zhang, Zuanming Jin, Xiumei Liu, Wanying Zhao, Xian Lin, Chao Jing, and Guohong Ma

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-42-16-3080&origin=search

We report the broadband terahertz (THz) radiation in ferromagnetic half-metallic Heusler alloy Co2MnSn${\mathrm{Co}}_2\mathrm{MnSn}$ thin film upon the irradiation of a femtosecond laser pulse at room temperature. The magnetic-, sample symmetry-, and pump fluence-dependent THz emission reveals that the THz radiation is originated from the magnetic-dipole radiation, i.e., the light-induced subpicosecond demagnetization. In addition, by optical pump-THz probe spectroscopy, we found that the photoexcited increase of the scattering rate of hot carriers thereby leads to the photoinduced negative THz conductivity in Co2MnSn${\mathrm{Co}}_2\mathrm{MnSn}$ thin film.

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