Landau and spin levels in InAs quantum wells resolved with inplane and parallel magnetic fields

High-mobility InAs quantum wells embedded between AlSb barriers are investigated by transport experiments at T = 80 mK in tilted magnetic fields. For magnetic fields applied normal to the sample surface the Landau level splitting is much larger than the spin splitting and minima are observed in the low-field Shubnikov-de Haas (SdH) oscillations predominantly at even integer filling factors. As the magnetic field is tilted away from the sample normal the spin splitting is enhanced relative to the Landau level splitting. We can observe SdH-like oscillations up to tilt angles where the spin splitting exceeds the Landau splitting by a factor of 3. From the angles at which spin levels of adjacent Landau levels can be made to coincide we can deduce a value for gm*, the effective electron g-factor times the effective mass. (C) 1998 Elsevier Science B.V. All rights reserved.