Numéro
J. Phys. IV France
Volume 12, Numéro 9, November 2002
Page(s) 263 - 264
DOI http://dx.doi.org/10.1051/jp4:20020411


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.


Abstract
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.



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