Effective mass and quantum lifetime in a Si/Si0.87Ge 0.13/Si two-dimensional hole gas

Abstract

Measurements of Shubnikov de Haas oscillations in the temperature range 0.3-2 K have been used to determine an effective mass of 0.23 m0 in a Si/Si0.87Ge0.13/Si two-dimensional hole gas. This value is in agreement with theoretical predictions and with that obtained from cyclotron resonance measurements. The ratio of the transport time to the quantum lifetime is found to be 0.8. It is concluded that the 4 K hole mobility of 11 000 cm2 V-1 s-1 at a carrier sheet density of 2.2×1011 cm-2 is limited by interface roughness and short-range interface charge scattering.