J. Phys. IV France
Volume 12, Numéro 9, November 2002
Page(s) 263 - 264

J. Phys. IV France
12 (2002) Pr9-263
DOI: 10.1051/jp4:20020411

Resistance fluctuations in a low density 2D hole gas in GaAs

R. Leturcq1, D. L'Hote1, R. Tourbot1, C.J. Mellor2 and M. Henini2

1  Service de Physique de l/'Etat Condensé, CEA-Saclay, 91191 Gif-sur-Yvette cedex, France
2  School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K.

We have measured the resistance fluctuations in 2D hole gases in GaAs quantum wells around the 2D "metal"-insulator transition (MIT) at temperatures between 35 and 700 mK. The magnitude of the noise spectrum has a l/ $^\alpha ( \alpha = 1)$ frequency dependence and increases strongly as the density is lowered. There is a qualitative change in the temperature dependence at a density pg, higher than the 2D MIT critical density pc. Moreover, the noise magnitude shows a scaling behaviour as a function of the resistance, which can be attributed to a percolation transition, as suggested by theories which explain the resistivity vs. temperature dependence near the 2D MIT.

© EDP Sciences 2002