Simultaneous evaluation of drift- and diffusion-induced spin-orbit fields in a (001) GaAs/AlGaAs two-dimensional electron gas

We experimentally investigate spatiotemporal dynamics of an electron spin ensemble in the coexistence of drift and diffusive spin motion in a (001) GaAs/AlGaAs two-dimensional electron gas. Electron spins simultaneously experience spin-orbit effective magnetic fields induced by each transport mechanism, resulting in the modulation of spin precession frequency. By employing scanning time-resolved Kerr rotation microscopy, we evaluate both drift and diffusion induced spin-orbit fields simultaneously from the spatiotemporal spin map. Based on the evaluated Rashba and Dresselhaus spin-orbit coefficients, we clarify the difference and the accuracy of the evaluated spin-orbit coefficients in each transport mechanism.