High-mobility InAs quantum wells embedded between AlSb barriers are investi
gated by transport experiments at T = 80 mK in tilted magnetic fields. For
magnetic fields applied normal to the sample surface the Landau level split
ting is much larger than the spin splitting and minima are observed in the
low-field Shubnikov-de Haas (SdH) oscillations predominantly at even intege
r filling factors. As the magnetic field is tilted away from the sample nor
mal the spin splitting is enhanced relative to the Landau level splitting.
We can observe SdH-like oscillations up to tilt angles where the spin split
ting exceeds the Landau splitting by a factor of 3. From the angles at whic
h spin levels of adjacent Landau levels can be made to coincide we can dedu
ce a value for gm*, the effective electron g-factor times the effective mas
s. (C) 1998 Elsevier Science B.V. All rights reserved.