WEAK-FIELD MAGNETORESISTANCE OF 2-DIMENSIONAL ELECTRONS IN IN0.53GA0.47AS INP HETEROSTRUCTURES IN THE PERSISTENT PHOTOCONDUCTIVITY REGIME/

The weak-field magnetoresistance of the two-dimensional electron gas ( 2DEG) in a modulation-doped In0.53Ga0.47As/InP heterostructure is stud ied as the state of the system is converted to a state with persistent photoconductivity by illuminating the sample with interband light. Th e concentration dependences of the parameters that characterize the ph ase (H-phi) and spin (H-s coherence are investigated, both in the low- concentration regime where only the first quantum-well subband is occu pied by carriers, and in the regime where the second subband is occupi ed. A qualitative description of all the features observed in experime nt is obtained by taking into account the redistribution of charge in the persistent photoconductivity state and the importance of processes that take place in the second quantum-well subband even when its occu pation is small. (C) 1998 American Institute of Physics. [S1063-7826(9 8)01809-2].