EXCHANGE CARRIER-CARRIER SCATTERING OF SPIN-POLARIZED 2-DIMENSIONAL ELECTRON-HOLE PLASMA - MONTE-CARLO STUDY

Thermalization of near-bandgap excited electron hole (e-h) plasma in an intrinsic GaAs quantum well is studied by Monte Carlo simulation. Carrier-carrier interaction is treated as two-particle e-e, e-h and h-h collisions due to screened Coulomb interaction. The indistinguishability of two colliding electrons (holes) is included by taking into account the exchange e-e (h-h) scattering between the electrons (holes) of like spin. The model is modified to the case of spin-polarized (SP) e-h plasma. We show that the thermalization of the sp plasma is several times slower than the thermalization of the spin-randomized plasma, when the density of photoexcited e-h pairs is 3 x 10(11) cm-2. The effect is due to the exchange e-e (h-h) scattering, which significantly weakens the direct Coulomb scattering in the dense sp plasma. This yields a chance to observe the exchange experimentally.