Positive magnetoresistance in In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As quantum well

Magnetotransport measurements have been carried out on In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As quantum wells in a temperature range between 1.5 and 77K. We have observed a large positive magnetoresistance in the low magnetic field range， but saturating in high magnetic fields. The magnetoresistance results from two occupied subbands in the two-dimensional electron gas. With the intersubband scattering considered， we obtained the subband mobility by analyzing the positive magnetoresistance. It is found that the second subband mobility is larger than that of the first due to the existence of the intersubband scattering.