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Author Ruzin, I. M. ♦ Cooper, N. R. ♦ Halperin, B. I.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ MATHEMATICAL MODELS ♦ ELECTRON DENSITY ♦ SIZE ♦ CRITICAL SIZE ♦ ELECTRIC CONDUCTIVITY ♦ ELECTRIC FIELDS ♦ ELECTRON CORRELATION ♦ ELECTRON GAS ♦ INHOMOGENEOUS FIELDS ♦ TEMPERATURE DEPENDENCE ♦ TEMPERATURE RANGE 0000-0013 K ♦ TENSOR FIELDS ♦ QUANTUM HALL EFFECT
Abstract We show that, at low temperatures, macroscopic inhomogeneities of the electron density in the interior of a finite sample cause a reduction in the measured conductivity peak heights {sigma}{sub {ital xx}}{sup max} compared to the universal values previously predicted for infinite homogeneous samples. This effect is expected to occur for the conductivity peaks measured in standard experimental geometries such as the Hall bar and the Corbino disk. At the lowest temperatures, the decrease in {sigma}{sub {ital xx}}{sup max}({ital T}) is found to saturate at values proportional to the difference between the adjacent plateaus in {sigma}{sub {ital xy}}, with a prefactor that depends on the particular realization of disorder in the sample. We argue that this provides a possible explanation of the {open_quote}{open_quote}nonuniversal scaling{close_quote}{close_quote} of {sigma}{sub {ital xx}}{sup max} observed in a number of experiments. We also predict an enhancement of the {open_quote}{open_quote}nonlocal{close_quote}{close_quote} resistance due to the macroscopic inhomogeneities. We argue that, in the Hall bar with a sharp edge, the enhanced {open_quote}{open_quote}nonlocal{close_quote}{close_quote} resistance and the size corrections to the {open_quote}{open_quote}local{close_quote}{close_quote} resistance {ital R}{sub {ital xx}} are directly related. Using this relation, we suggest a method by which the finite-size corrections may be eliminated from {ital R}{sub {ital xx}} and {ital R}{sub {ital xy}} in this case. {copyright} {ital 1996 The American Physical Society.}
ISSN 01631829
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-01-01
Publisher Place United States
Journal Physical Review, B: Condensed Matter
Volume Number 53
Issue Number 3


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