Observation of two relaxation mechanisms in transport between spin split edge states at high imbalance
E.V. Deviatov, A. Wurtz, A. Lorke, M.Yu. Melnikov, V.T. Dolgopolov, D. Reuter, A.D. Wieck
Abstract
Using a quasi-Corbino geometry to directly study electron transport between spin-split edge states, we find a pronounced hysteresis in the I-V curves, originating from slow relaxation processes. We attribute this long-time relaxation to the formation of a dynamic nuclear polarization near the sample edge. The determined characteristic relaxation times are 25 s and 200 s which points to the presence of two different relaxation mechanisms. The two time constants are ascribed to the formation of a local nuclear polarization due to flip-flop processes and the diffusion of nuclear spins.