ANOMALOUS SUBBAND LANDAU LEVEL COUPLING IN GaAs-AlGaAs HETEROJUNCTIONS

G.C. Wiggins, D.R. Leadley, D.J. Barnes, R.J. Nicholas and M.A. Hopkins,
Clarendon Laboratory, Parks Road, Oxford OX1 3PU, U.K.

J.J. Harris and C.T. Foxon
Philips Research Laboratories, Redhill, Surrey RH1 5HA. U.K.

Electric subband energy differences are measured in high mobility GaAs-GaAlAs heterojunctions by tilted field cyclotron resonance and magnetotransport as a function of carrier density and temperature. At small tilt angles we see unusual resonant subband Landau level coupling, with an overlap of the branches of the coupling rather than the expected anticrossing. From the measured subband energies we see the samples have a very low depletion charge and that E₀₁ increases with temperature at a rate of 0.037 meVK^-1.

High Magnetic Fields in Semiconductor Physics III, ed. G. Landwehr, Springer Series in Solid State Sciences Vol. 101 (Springer, Berlin, 1992), p. 562.