Scattering mechanisms in InAs–AlSb quantum wells

Abstract

High-quality InAs–AlSb quantum wells have been grown by molecular beam epitaxy. The Drude scattering time τ D as well as the quantum scattering times τ Q have been evaluated from low-temperature magnetotransport experiments. While the τ 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 τ D/ τ 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 1×10 11 cm −2 kbar −1 at liquid He temperatures.