Spin-Splitting and Effective Mass of the 2-Dimensional Electron Gas in an Al0.6Ga0.4Sb/InAs Single Quantum Well

ABSTRACTThe 2-dimensional electron gas (2DEG) in an Al0.6Ga0.4Sb/InAs single quantum well (SQW) is studied using cyclotron resonance (CR) and Shubnikov - de Haas (SdH) techniques. SdH results show spin-splitting in Landau levels at magnetic field strength (B) as low as 1.5T. The effective mass (m*) of the 2DEG was obtained from the peak positions of the CR transmission spectra. The results exhibit oscillatory behavior as a function of B. The m* value extracted from die temperature dependence of the SdH oscillations is in good agreement with the average value of m* obtained from CR measurements. The effective mass is calculated as a function of B using an electron self-energy model based on the Hartree-Fock approximation. The calculated m* values also show oscillatory behavior similar to that of the measured CR m*. Both experiment and theory show that m* maxima are shifted from the integral values (both odd and even) of the filling factors.