Conduction threshold and pinning frequency of magnetically induced Wigner
F. I. B. Williams, P. A. Wright, R. G. Clark, E. Y. Andrei, G. Deville,
D. C. Glattli, O. Probst, B. Etienne, C. Dorin, C. T. Foxon, and J. J.
Service de Physique du Solide et de Résonance Magnétique,
Centre d'Etudes Nucléaires, Saclay, 91191 Gif-sur-Yvette, France
Clarendon Laboratory, Oxford University, Oxford OX1 3PU, United
Department of Physics, Rutgers University, Piscataway, New Jersey
Laboratoire de Microstructures et de Microélectronique, Centre
National de la Recherche Scientifique, 92220 Bagneux, France
Philips Research, Redhill, Surrey RH1 5HA, United Kingdom(Received
14 September 1990)
The 2D quantum system of electrons at a GaAs/GaAlAs heterojunction
in high magnetic field at low temperature is shown to exhibit conduction
typical of pinned charge-density waves. Crossover from Ohmic conduction
occurs on the same boundary at which radio-frequency resonances signal
the onset of transverse elasticity. A further small non-Ohmic region is
isolated from the main area by a v=1/5 quantum-Hall-effect phase.
The relationship found between the threshold conduction field and the resonance
frequency is well accounted for by a model of pinned electron crystallites.