Contribution to the theory of spin relaxation at finite temperatures in the odd-filling quantum Hall effect regime

Spin relaxation in a two-dimensional electron gas (2D EG) is treated as the establishment of equilibrium in a gas of spin excitons as a result of proc esses that change the number of spin excitons. Coalescence is the dominant channel above a temperature of the order of 1 K. The coalescence of exciton s can occurr as a result of spin-orbit and Coulomb interactions in the 2D E G. The rate of coalescence falls exponentially at low temperatures. The rel axation time is calculated, and the critical temperature below which the ma in annihilation process becomes that due to the exciton-phonon interaction is determined. (C) 1999 American Institute of Physics. [S0021-3640(99)01020 -8].