Highly Enhanced Thermopower in Two-Dimensional Electron Systems at Millikelvin Temperatures

Goswami, Srijit and Siegert, Christoph and Baenninger, Matthias and Pepper, Michael and Farrer, Ian and Ritchie, David A and Ghosh, Arindam (2009) Highly Enhanced Thermopower in Two-Dimensional Electron Systems at Millikelvin Temperatures. In: Physical Review Letters, 103 (2). 026602.

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Abstract

We report experimental observation of an unexpectedly large thermopower in mesoscopic two-dimensional (2D) electron systems in GaAs/AlGaA heterostructures at sub-Kelvin temperatures and zero magnetic field. Unlike conventional nonmagnetic high-mobility 2D systems, the thermopower in our devices increases with decreasing temperature below 0.3 K, reaching values in excess of 100 mu V/K, thus exceeding the free electron estimate by more than 2 orders of magnitude. With support from a parallel study of the local density of states, we suggest such a phenomenon to be linked to intrinsic localized states and many-body spin correlations in the system.

Item Type:	Journal Article
Publication:	Physical Review Letters
Publisher:	The American Physical Society
Additional Information:	Copyright of this article belongs to The American Physical Society.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	12 Aug 2009 08:09
Last Modified:	19 Sep 2010 05:39
URI:	http://eprints.iisc.ac.in/id/eprint/21832

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