||Systematic investigations of transient response of nuclear spins in the presence of polarized electrons
Rasly, Mohmoud ,
Lin, ZhichaoUemura, Tetsuya
, p.184415 , 2017-11-13 , American Physical Society (APS)
We electrically probed the transient response of nuclear spins in an n-GaAs channel by performing Hanle signal and spin-valve signal measurements on an all-electrical spin-injection device having a half-metallic spin source of Co2MnSi. Furthermore, we simulated the Hanle and spin-valve signals by using the time evolution of nuclear-spin polarization under the presence of polarized electron spins by taking both T-1e and T-1 into consideration, where T-1e(-1) is the polarization rate of nuclear spins through the transfer of angular momentum from polarized electron spins and T-1(-1) is the depolarization rate of nuclear spins through the interaction with the lattice. The simulation results reproduced our experimental results on all the nuclear-spin-related phenomena appearing in the Hanle and spin-valve signals at different measurement conditions, providing quantitative explanation for the transient response of nuclear spins in GaAs to a change in magnetic fields and an estimate of the time scales of T-1e and T-1. These experimental and simulated results will deepen the understanding of nuclear-spin dynamics in semiconductors.