We have studied the zero magnetic field resistivity of unique high- mobility two-dimensional electron system in silicon. At very low electron density (but higher than some sample-dependent critical value, ncr∼1011 cm−2), CONVENTIONAL WEAK LOCALIZATION IS OVERPOWERED BY A SHARP DROP OF RESISTIVITY BY AN ORDER OF MAGNITUDE with decreasing temperature below 1--2 K. No further evidence for electron localization is seen down to at least 20 mK. For ns<Ncr, the sample is insulating. The resistivity is empirically found to SCALE WITH TEMPERATURE BOTH BELOW AND ABOVE ncr WITH A SINGLE PARAMETER which approaches zero at ns=ncr suggesting a metal/ insulator phase transition.
@article{arxiv.cond-mat/9405082,
title = {Possible Metal/Insulator Transition at B=0 in Two Dimensions},
author = {S. V. Kravchenko and G. V. Kravchenko and J. E. Furneaux and V. M. Pudalov and M. D'Iorio},
journal= {arXiv preprint arXiv:cond-mat/9405082},
year = {2009}
}
Comments
10 pages; REVTeX v3.0; 3 POSTSCRIPT figures available upon request; to be published in PRB, Rapid Commun