Disappearance of Magnetophonon Resonance at High Magnetic Fields in GaAs-GaAlAs Heterojunctions

D.R. Leadley¹, R.J. Nicholas¹, J. Singleton^1,4, W. Xu², F.M. Peeters², J.T. Devreese², L. van Bockstal³, F. Herlach³, J.A.A.J. Perenboom⁴, J.J. Harris⁵and C.T. Foxon⁶

1. Departement Natuurkunde, Universiteit Antwerpen (UIA), Universiteitsplein 1, B-2610 Antwerpen, Belgium
2. Univerisity of Nijmegen, Toerooiveld 1, NL-6525 ED, Nijmegen, The Netherlands
3. Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001, Leuven, Belgium.
4. Semiconductor IRC, Imperial College, London. SW7 2BZ, UK
5. Department of Physics, University Park, Nottingham, NG7 2RD, UK

Magnetophonon resonance is studied in the resistivity of high mobility GaAs-GaAlAs heterojunctions. At high magnetic fields the oscillation amplitude decreases, leading to the complete disapperance of the fundamental resonance in some cases. This is in complete contrast to the behaviour seen in previous studies on many different materials which show an exponentially damped series of oscillations. The disapperance is explained by fully self-consistent calculations, including all the scattering processes to calculate the density of states and the resistivity. We find the Landau level width oscillates in field and the resonance amplitudes are determined by the relative importance of the elastic and inelastic scattering rates.

Proc. EP2DS-10 Newport, 1993
Surface Science 305, 327 (1994).