TRANSPORT OF MAGNETOEXCITONS IN SINGLE AND COUPLED QUANTUM-WELLS

The transport relaxation time tau(P) and the mean free path of magneto excitons in single and coupled quantum wells are calculated (P is the magnetic momentum of the magnetoexciton). We present the results for m agnetoexciton scattering in a random held due to (i) quantum well widt h fluctuations, (ii) composite fluctuations and (iii) ionized impuriti es. The time tau(P) depends nonmonotonously on P in the case (ii) and in the case (i), (iii) for D/l smaller than some critical value (D is the interwell separation, l = root (H) over bar c/eH is the magnetic l ength). For D/l much greater than 1 the transport relaxation time incr eases monotonously with P. The magnetoexciton mean free path lambda(P) has a maximum at P not equal 0 in the cases (i), (iii). It decreases with increasing D/l. The mean free path calculated for the case (ii) m ay have two maxima One of them disappears with the variation of the ra ndom fields parameters. The maximum of lambda(P) increases with H for types (i, iii) of scattering processes and decreases in the case (ii).