Scattering mechanisms in InAs-AlSb quantum wells

High-quality InAs-AlSb quantum wells have been grown by molecular beam epitaxy. The Drude scattering time tau(D) as well as the quantum scattering times tau(Q) have been evaluated from low-temperature magnetotransport experiments. While the tau(D) increases monotonically with carrier density, the quantum scattering time fluctuates as a function of carrier density depending on the cool-down cycle. For high-mobility samples we find that the ratio tau(D)/tau(Q) can be as high as 88 indicating long-range potential fluctuations. If hydrostatic pressure is applied to the sample the carrier density is reduced by about 1 x 10(11) cm(-2) kbar(-1) at liquid He temperatures. (C) 1998 Published by Elsevier Science B.V. All rights reserved.