Electron spin dynamics in multi-energy level systems under the excitation of circular polarization modulated continuous-wave laser

Abstract

Time-resolved photoluminescence spectroscopy under the excitation of circular polarization modulated continuous-wave laser can quantitatively extract the electron spin polarization degrees and electron spin relaxation time, providing an important tool to detect electron spin dynamics. We theoretically analyze the electron spin dynamics in four-, six- and eight-energy level systems under the excitation of circular polarization modulated continuous-wave laser by solving the rate equations of electron population. The relationship between the time-resolved photoluminescence spectra and the spin information of the spin system is provided. The electron spin polarization degrees of the ground and excited states, the establishment time of the steady-state spin polarization and the electron spin relaxation time can be directly derived from the time-resolved photoluminescence spectra. And the theoretical model is verified experimentally by the measurement of electron spin dynamics in Ce3+: YAG crystal.