Nonexponential decoherence of collective spin states in 2DES probed by time-resolved Kerr rotation

The spin coherence of two-dimensional electrons is determined by two independent mechanisms: a single particle relaxation owing to spatially fluctuating magnetic field, and a many-particle exchange interaction maintaining collective precession of the electron spins with a common Larmor frequency. In this study, we investigate the structure of a time-resolved Kerr rotation signal for the different spin states of two-dimensional electron system subjected to the quantizing magnetic field. At low temperatures, when spin-spin correlations define the ground state of the two-dimensional electron system, our data show a nonlinear damping of Larmor oscillations. The amplitude and the correlation length of the fluctuating magnetic field acting on individual electron spins are estimated.

Automated summary

The study investigates the structure of a time-resolved Kerr rotation signal for different spin states of a two-dimensional electron system subjected to a quantizing magnetic field. At low temperatures, with spin-spin correlations defining the ground state, the data show nonlinear damping of Larmor oscillations.