Anisotropic Fermi Contour of (001) GaAs Holes in Parallel Magnetic   Fields
  We report a severe, spin-dependent, Fermi contour anisotropy induced by parallel magnetic field in a high-mobility (001) GaAs two-dimensional hole system. Employing commensurability oscillations created by a unidirectional, surface-strain-induced, periodic potential modulation, we directly probe the anisotropy of the two spin subband Fermi contours. Their areas are obtained from the Fourier transform of the Shubnikov-de Haas oscillations. Our findings are in semi-quantitative agreement with the results of parameter-free calculations of the energy bands. 
D. Kamburov, M. Shayegan, R. Winkler, L. N. Pfeiffer, K. W. West, and   K. W. Baldwin
cond-mat.mes-hall