Conduction threshold and pinning frequency of magnetically induced Wigner solid

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. Harris
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 Kingdom
Department of Physics, Rutgers University, Piscataway, New Jersey 08855
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.