Rashba effect on spin-resolved carrier dynamics excited by circularly-polarized light from first-principles

Recent optical pump/X-ray probe experiments have shown that circularly polarized light can be used to manipulate spin states in materials exhibiting strong Rashba splitting like organo-metallic halide perovskites (OMHPs) and transition metal dichalcogenides (TMDs). The ability to exploit the dynamics of spin makes these materials lucrative candidates for spin-optoelectronic applications [1]. While considerable experimental work has been performed on probing the spin dynamics in TMDs and OMHPs, efforts to model this ultrafast spin-dependent dynamics of charge carriers have so far been limited primarily to effective model Hamiltonians. A key challenge is accounting for electron-phonon scattering effects on the spin dynamics explicitly, due to the requirement of ultra-fine Brillouin-zone sampling arising from the disparate energy scales of electrons and phonons. We present a completely parameter-free ab initio approach to study spin and carrier dynamics, using Wannier functions to facilitate efficient calculation of electron-phonon scattering. Using this approach, we present calculations of spin-resolved photo-excited carrier distributions and phonon-assisted spin relaxation times for TMDs and ferroelectric oxides.

[1] Y. Ping and J. Z. Zhang. J. Phys. Chem. Lett. 9, 6103 (2018).