Determination of the effective mass of the two-dimensional electron gas occupied at two subbands in In0.65Ga0.35As strained single quantum wells by using the fast Fourier transformation and the inverse fast Fourier transformation analyses

Abstract

The determination of the effective mass of the two-dimensional electron gas (2DEG) and nonparabolicity effects in modulation-doped In0.65Ga0.35As/In0.52Al0.48As single quantum well were investigated by temperature-dependent Shubnikov–de Haas (S–dH) measurements and fast Fourier transformation (FFT) and the inverse FFT (IFFT) analyses. The result of the angular-dependent S–dH measurements clearly demonstrated the occupation of two subbands in the quantum wells by the 2DEGs. The electron effective masses determined from temperature-dependent S–dH measurements and the FFT and IFFT analyses were 0.05869 and 0.05385me for the first and zeroth subbands, respectively. The electron effective masses obtained from the S–dH measurements and the FFT and IFFT analyses measurements qualitatively satisfy the nonparabolicity behavior in the In0.65Ga0.35As single quantum well. The electronic subband energies, the subband energy wavefunctions, and the Fermi energy in the In0.65Ga0.35As single quantum wells were calculated by a self-consistent method taking into account the exchange-correlation effect, the strain effect, and the nonparabolicity effect.