Control of Electron Spin Coherence Using Landau Level Quantization in a Two-Dimensional Electron Gas

V. Sih, W. H. Lau, R. C. Myers, A. C. Gossard, M. E. Flatté, D. D. Awschalom

Published 2004-07-26Version 1

Time-resolved optical measurements of electron spin dynamics in modulation doped InGaAs quantum wells are used to explore electron spin coherence times and spin precession frequencies in a regime where an out of plane magnetic field quantizes the states of a two-dimensional electron gas into Landau levels. Oscillatory features in the transverse spin coherence time and effective g-factor as a function of applied magnetic field exhibit a correspondence with Shubnikov-de Haas oscillations, illustrating a coupling between spin and orbital eigenstates. We present a theoretical model in which inhomogeneous dephasing due to the population of different Landau levels limits the spin coherence time and captures the essential experimental results.