Highly Enhanced Thermopower in Two-Dimensional Electron Systems at Millikelvin Temperatures.
PHYS REV LETT
, Article 026602. 10.1103/PhysRevLett.103.026602.
We report experimental observation of an unexpectedly large thermopower in mesoscopic two-dimensional (2D) electron systems in GaAs/AlGaAs 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.
|Title:||Highly Enhanced Thermopower in Two-Dimensional Electron Systems at Millikelvin Temperatures|
|Open access status:||An open access version is available from UCL Discovery|
|Additional information:||© 2009 The American Physical Society|
|Keywords:||THERMOELECTRIC-POWER, TRANSPORT-PROPERTIES, LATTICE, GAS, RESISTIVITY, LOCALIZATION|
|UCL classification:||UCL > School of BEAMS > Faculty of Engineering Science > Electronic and Electrical Engineering|
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