hide
Free keywords:
plateau-insulator transition; scaling; critical behavior
Abstract:
We have measured the quantum critical behavior of the plateau-insulator
(PI) transition in a low-mobility InGaAs/GaAs quantum well. The
longitudinal resistivity measured for two different values of the
electron density follows an exponential law, from which we extract
critical exponents kappa = 0.54 and 0.58, in good agreement with the
value (kappa = 0.57) previously obtained for an InGaAs/InP
heterostructure. This provides evidence for a non-Fermi liquid critical
exponent. By reversing the direction of the magnetic field we find that
the averaged Hall resistance remains quantized at the plateau value
h/e(2) through the PI transition. From the deviations of the Hall
resistance from the quantized value, we obtain the corrections to
scaling. (C) 2003 Elsevier B.V. All rights reserved.
