Resistance noise scaling in a dilute two-dimensional hole system in GaAs.
We have measured the resistance noise of a two-dimensional (2D) hole system in a high mobility GaAs quantum well, around the 2D metal-insulator transition (MIT) at zero magnetic field. The normalized noise power S(R)/R(2) increases strongly when the hole density p(s) is decreased, increases slightly with temperature (T) at the largest densities, and decreases strongly with T at low p(s). The noise scales with the resistance, S(R)/R(2) approximately R2.4, as for a second order phase transition such as a percolation transition. The p(s) dependence of the conductivity is consistent with a critical behavior for such a transition, near a density p(*) which is lower than the observed MIT critical density p(c).
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Service de Physique de l'Etat Condensé, CEA/DSM, CE Saclay, F-91191 Gif-sur-Yvette, France.
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Tourbot
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Mellor
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Henini
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