Signature of inverse orbital Hall effect in silicon studied using time-resolved terahertz polarimetry

2025/12/22 by Ami Mi Shirai, Shirai, Ami Mi, Kota Aikyo +15
Engineering · Physics and Astronomy · #Terahertz technology and applications #Topological Materials and Phenomena #Quantum and electron transport phenomena

paper · doi:10.48550/arxiv.2512.19065

Abstract

We investigated the anomalous Hall conductivity induced in silicon by circularly polarized light at room temperature using near-infrared (NIR) pump-terahertz (THz) probe spectroscopy. The time-resolved detection scheme eliminates the large nonlinear current generated by the field-induced circular photogalvanic effect, allowing exclusive observation of a long-lived anomalous Hall conductivity of photocarriers that depends on the helicity of NIR light. The magnitude of this conductivity is comparable to that of GaAs despite silicon's much weaker spin-orbit coupling, and its robustness against NIR photon energy rules out a spin-polarization-based origin, which occurs only in the vicinity of the bandgap. These results suggest the emergence of the inverse orbital Hall effect, paving the way for silicon-based orbitronics.

Citations

• Quantum Kinetic Anatomy of Electron Angular Momenta Edge Accumulation
• Wannier interpolation of spin accumulation coefficient
• What is a proper definition of spin current? -- Lessons from the Kane-Mele Model

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