Publications
Lee Wienkes
Anomalous magnetic field dependence of the T1 spin lifetime in a lightly-doped GaAs sampleJ. S. Colton, M. E. Heeb, P. Schroeder, A. Stokes, L. R. Wienkes, and A. S. Bracker, Phys. Rev. B
Abstract
The T1 spin lifetime of a lightly doped n-type GaAs sample has been measured via time-resolved polarization spectroscopy under a number of temperature and magnetic field conditions. Lifetimes up to 19 µs have been measured. The magnetic field dependence of T1 shows a nonmonotonic behavior, where the spin lifetime first increases, then decreases, then increases again with field. The initial increase in T1 is understood to be due to correlation between electrons localized on donors. The decrease in T1 is likely due to phonon-related spin-orbit relaxation. The final increase in T1 with B indicates a suppression of the spin-orbit relaxation that may involve a level-crossing related cusp in the Rashba or Dresselhaus contributions to relaxation, or may arise from an unknown source.