2020/09/02 by Masashi Kawaguchi, Kawaguchi, Masashi, Hana Hirose +9
Physics and Astronomy · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Photonic Crystals and Applications #Quantum optics and atomic interactions #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2009.01388
openalex publication_date 2020/09/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We have studied helicity dependent photocurrent (HDP) in Bi-based Dirac semimetal thin films. HDP increases with film thickness before it saturates, changes its sign when the majority carrier type is changed from electrons to holes and takes a sharp peak when the Fermi level lies near the charge neutrality point. These results suggest that irradiation of circularly polarized light to Dirac semimetals induces an effective magnetic field that aligns the carrier spin along the light spin angular momentum and generates a spin current along the film normal. The effective magnetic field is estimated to be orders of magnitude larger than that caused by the inverse Faraday effect (IFE) in typical transition metals. We consider the small effective mass and the large g-factor, characteristics of Dirac semimetals with strong spin orbit coupling, are responsible for the giant IFE, opening pathways to develop systems with strong light-spin coupling.