2018/03/19 by Yuto Kinoshita, Noriaki Kida, N. Kida +5
Chemistry · Engineering · Physics and Astronomy · #Chemistry #Circular polarization #Condensed matter physics #Electromagnetic radiation #Electron #Excitation #Femtosecond #Laser #Optics #Optoelectronics #Physics #Polarization (electrochemistry) #Quantum and electron transport phenomena #Semiconductor #Spin polarization #Terahertz radiation #Terahertz technology and applications #Topological Materials and Phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.97.161104
published as Phys. Rev. B 97, 161104 (2018) · 23 pages including Supplemental Materials
arxiv created 2018/03/19 · openalex created_date 2018/03/29 · openalex publication_date 2018/04/05 · arxiv updated 2018/04/11 · openalex updated_date 2026/08/05
The spin-splitting energy bands induced by the relativistic spin-orbit interaction in solids provide a new opportunity to manipulate the spin-polarized electrons on the subpicosecond timescale. Here, we report one such example in a bulk Rashba-type polar semiconductor BiTeBr. Strong terahertz electromagnetic waves are emitted after the resonant excitation of the interband transition between the Rashba-type spin-splitting energy bands with a femtosecond laser pulse circularly polarized. The phase of the emitted terahertz waves is reversed by switching the circular polarization. This suggests that the observed terahertz radiation originates from the subpicosecond spin-polarized photocurrents, which are generated by the asymmetric depopulation of the Dirac state. Our result provides a way for the current-induced terahertz radiation and its phase control by the circular polarization of incident light without external electric fields.