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Re-entrant insulator-metal-insulator transition at B=0 in a two dimensional hole gas

A. R. Hamilton·M. Y. Simmons·M. Pepper·E. H. Linfield·P. D. Rose·D. A. Ritchie
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Abstract

We report the observation of a re-entrant insulator--metal--insulator transition at B=0 in a two dimensional (2D) hole gas in GaAs at temperatures down to 30mK. At the lowest carrier densities the holes are strongly localised. As the carrier density is increased a metallic phase forms, with a clear transition at σ= ~5e^2/h. Further increasing the density weakens the metallic behaviour, and eventually leads to the formation of a second insulating state for σ> ~50e^2/h. In the limit of high carrier densities, where k_F.l is large and r_s is small, we thus recover the results of previous work on weakly interacting systems showing the absence of a metallic state in 2D.

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A. R. Hamilton, M. Y. Simmons, M. Pepper, E. H. Linfield, P. D. Rose, D. A. Ritchie. 1998-08-11. Re-entrant insulator-metal-insulator transition at B=0 in a two dimensional hole gas. https://doi.org/10.1103/physrevlett.82.1542

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