2002/04/24 by C. E. Yasin, Yasin, C. E., M. Y. Simmons +11
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Strongly Correlated Electrons (cond-mat.str-el) #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.cond-mat/0204519
5 pages, 4 figures
arxiv created 2002/06/13 · arxiv updated 2009/11/30
We investigate the relationship between the quantum Hall extended states and the apparent B=0 `metal'-insulator transition in extremely low density, high quality two-dimensional n-GaAs systems (μpeak ~ 2 x 107 cm2/Vs). The combination of small effective mass and high quality allow us to resolve the continued floating up in energy of the extended states down to very low magnetic fields, B=0.015T, despite an apparent `metal'-insulator transition at B = 0. We present a modified global phase diagram which brings together conflicting data in the literature from different material systems, and reconciles the differences as to the fate of the extended states as B -> 0.