Valley polarization dynamics of photoinjected carriers at the band edge in room-temperature silicon studied by terahertz polarimetry
arXiv:2412.14564 · doi:10.1103/PhysRevB.111.L121201
Abstract
Sixfold-degenerate valleys in Si have attracted considerable attention for valleytronics application. Using optical pump-terahertz (THz) probe spectroscopy, we study the dynamics of valley polarization in bulk Si(001) at room temperature. Linearly polarized pump pulses excite electrons and holes with asymmetric distributions in momentum space, leading to in-plane anisotropic conductivity. By varying the polarization directions of the pump light relative to the in-plane crystalline axes, the valley polarization of electrons and the momentum asymmetry of holes are separately probed through observing the polarization rotation of THz pulses. We demonstrate that the valley relaxation time of electrons near the conduction band minimum exceeds 1.5 ps at room temperature, in good agreement with theoretically calculated intervalley phonon scattering with f process. This work paves the way for Si-based room-temperature valleytronics.
arXiv comment17 pages, 3 figures
References in corpus (19)
- Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
- Control of valley polarization in monolayer MoS2 by optical helicity
- Valley contrasting physics in graphene: magnetic moment and topological transport
- The Valley Hall Effect in MoS2 Transistors
- Valley filter and valley valve in graphene
- Valley susceptibility of an interacting two-dimensional electron system
- Exchange in silicon-based quantum computer architecture
- Controllable valley splitting in silicon quantum devices
- Valley splitting of AlAs two-dimensional electrons in a perpendicular magnetic field
- Optical Birefringence and Dichroism of Cuprate Superconductors in the THz regime
- Exciton Mott transition in Si Revealed by Terahertz Spectroscopy
- Thermoelectric Band Engineering: The Role of Carrier Scattering
- Intrinsic coherent acoustic phonons in indirect band gap semiconductors Si and GaP
- Differentiating Photoexcited Carrier and Phonon Dynamics in the Δ, L, and Γ Valleys of Si(100) with Transient Extreme Ultraviolet Spectroscopy
- Cooling Dynamics of Photoexcited Carriers in Si Studied by Using Optical Pump and Terahertz Probe Spectroscopy
- Optical parametric amplification of phase-stable terahertz-to-midinfrared pulses studied in the time domain
- Ultrafast hot carrier relaxation in silicon monitored by phase-resolved transient absorption spectroscopy
- Observation of Terahertz Spin Hall Conductivity Spectrum in GaAs with Optical Spin Injection
- Contactless determination and parametrization of charge carrier mobility in silicon as a function of injection level and temperature using time-resolved THz spectroscopy