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Related papers: Density-dependent thermopower oscillations in meso…

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We report thermopower ($S$) and electrical resistivity ($\rho_{2DES}$) measurements in low-density (10$^{14}$ m$^{-2}$), mesoscopic two-dimensional electron systems (2DESs) in GaAs/AlGaAs heterostructures at sub-Kelvin temperatures. We…

Strongly Correlated Electrons · Physics 2015-03-20 Vijay Narayan , M. Pepper , J. Griffths , H. Beere , F. Sfigakis , G. Jones , D. Ritchie , A. Ghosh

We present thermal and electrical transport measurements of low-density (10$^{14}$ m$^{-2}$), mesoscopic two-dimensional electron systems (2DESs) in GaAs/AlGaAs heterostructures at sub-Kelvin temperatures. We find that even in the…

We measure the temperature of a 2D electron gas in GaAs from the thermopower of a one-dimensional ballistic constriction, using the Mott relation to confirm the calibration from the electrical conductance. Under hot electron conditions,…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 N. J. Appleyard , J. T. Nicholls , M. Y. Simmons , W. R. Tribe , M. Pepper

We investigate the striking absence of strong localisation observed in mesoscopic two-dimensional electron gases (2DEGs) (Baenninger et al 2008 Phys. Rev. Lett. 100 1016805, Backes et al 2015 Phys. Rev. B 92 235427) even when their…

Mesoscale and Nanoscale Physics · Physics 2016-05-25 Dirk Backes , Richard Hall , Michael Pepper , Harvey Beere , David Ritchie , Vijay Narayan

This paper reports thermopower and conductivity measurements through the metal-insulator transition for 2-dimensional electron gases in high mobility Si-MOSFETs. At low temperatures both thermopower and conductivity show critical behaviour…

Strongly Correlated Electrons · Physics 2009-11-07 R. Fletcher , V. M. Pudalov , A. D. B. Radcliffe , C. Possanzini

The diffusion of energy that is locally deposited into two-dimensional electron gases by Joule heating generates transverse voltages across devices with broken symmetry. For mesoscopic structures characterized by device dimensions…

Mesoscale and Nanoscale Physics · Physics 2014-11-19 Stephan Rojek , Jürgen König

This letter reports thermopower and conductivity measurements through the metal-insulator transition for 2-dimensional electron gases in high mobility Si-MOSFET's. At low temperatures both thermopower and conductivity show critical behavior…

Disordered Systems and Neural Networks · Physics 2007-05-23 R. Fletcher , V. M. Pudalov , A. D. B. Radcliffe , C. Possanzini

We report experimental observation of an unexpectedly large thermopower in mesoscopic two-dimensional (2D) electron systems on GaAs/AlGaAs heterostructures at sub-Kelvin temperatures and zero magnetic field. Unlike conventional non-magnetic…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Srijit Goswami , Christoph Siegert , Matthias Baenninger , Arindam Ghosh , Michael Pepper , Ian Farrer , David A. Ritchie

We report the discovery of two-dimensional electron gas (2DEG) at the surface of thermoelectric material In$_4$Se$_3$ by angle-resolved photoemission spectroscopy. The observed 2DEG exhibits a nearly isotropic band dispersion with a…

Mesoscale and Nanoscale Physics · Physics 2016-06-22 K. Fukutani , T. Sato , P. V. Galiy , K. Sugawara , T. Takahashi

We present thermopower measurements on a high electron mobility two-dimensional electron gas (2DEG) in a thin suspended membrane.We show that the small dimension of the membrane substantially reduces the thermal conductivity compared to…

Mesoscale and Nanoscale Physics · Physics 2015-06-03 M. Schmidt , G. Schneider , Ch. Heyn , A. Stemmann , W. Hansen

We have measured the magneto-resistance of a two-dimensional electron gas (2DEG) under continuous microwave irradiation as a function of electron density and mobility tuned with a metallic top-gate. In the entire range of density and…

Strongly Correlated Electrons · Physics 2009-11-11 B. Simovic , C. Ellenberger , K. Ensslin , Wegscheider

We review some of our recent experimental studies on low-carrier concentration, mesoscopic two-dimensional electron gases (m2DEGs). The m2DEGs show a range of striking characteristics including a complete avoidance of the strongly localised…

Mesoscale and Nanoscale Physics · Physics 2016-11-21 Vijay Narayan , Michael Pepper , David Ritchie

A simple hot electron thermocouple is realized in a two-dimensional electron system (2DES) and used to measure the diffusion thermopower of the 2DES at zero magnetic field. This hot electron technique, which requires no micron-scale…

Mesoscale and Nanoscale Physics · Physics 2009-07-27 W. E. Chickering , J. P. Eisenstein , J. L. Reno

We report electrical and magneto transport measurements in mesoscopic size, two-dimensional (2D) electron gas in a GaAs quantum well. Remarkably, we find that the probe configuration and sample geometry strongly affects the temperature…

Mesoscale and Nanoscale Physics · Physics 2019-12-06 G. M. Gusev , A. D. Levin , E. V. Levinson , A. K. Bakarov

We perform combined resistivity and compressibility studies of two-dimensional hole and electron systems which show the apparent metal-insulator transition - a crossover in the sign of dR/dT with changing density. No thermodynamic anomalies…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 G. D. Allison , E. A. Galaktionov , A. K. Savchenko , S. S. Safonov , M. M. Fogler , M. Y. Simmons , D. A. Ritchie

We study conductance fluctuations in a two-dimensional electron gas as a function of chemical potential (or gate voltage) from the strongly insulating to the metallic regime. Power spectra of the fluctuations decay with two distinct…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 Dragana Popović , S. Washburn

We calculate the single-particle states of a two-dimensional electron gas (2DEG) in a perpendicular quantizing magnetic field, which is periodic in one direction of the electron layer. We discuss the modulation of the electron density in…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Ulrich J. Gossmann , Andrei Manolescu , Rolf R. Gerhardts

We demonstrate tunable transverse rectification in a density-modulated two-dimensional electron gas (2DEG). The density modulation is induced by two surface gates, running in parallel along a narrow stripe of 2DEG. A transverse voltage in…

Mesoscale and Nanoscale Physics · Physics 2012-11-19 A. Ganczarczyk , S. Rojek , A. Quindeau , M. Geller , A. Hucht , C. Notthoff , D. Reuter , A. D. Wieck , J. König , A. Lorke

Ultrathin layers of semiconducting molybdenum disulfide (MoS2) offer significant prospects in future electronic and optoelectronic applications. Although an increasing number of experiments bring light into the electronic transport…

Mesoscale and Nanoscale Physics · Physics 2014-07-10 Jing Wu , Hennrik Schmidt , Amara Kiran Kumar , Xiangfan Xu , Goki Eda , Barbaros Özyilmaz

The amplitude V_0 of unidirectional periodic potential modulation introduced by a surface grating into a two-dimensional electron gas (2DEG) formed at AlGaAs/GaAs heterointerface is measured as a function of electron density n_e by…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Akira Endo , Yasuhiro Iye
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