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Related papers: Metallic behavior in Si/SiGe 2D electron systems

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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…

High mobility and dilute two-dimensional electron systems exhibit metallic behavior down to the lowest experimental temperatures. In studies of ionic liquid gated insulating silicon, we have observed transitions to a metallic state in low…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 JJ Nelson , A. M. Goldman

We report the observation of a metal-insulator transition (MIT) in a two- dimensional electron gas (2DEG) in a Si/SiGe heterostructure at zero magnetic field. On going through the MIT we observe the corresponding evolution of the magnetic…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 E. B. Olshanetsky , V. Renard , Z. D. Kvon , J. C. Portal , N. J. Woods , J. Zhang , J. J Harris

We compare the effects of temperature, disorder and parallel magnetic field on the metallic-like temperature dependence of the resistivity. We found a similarity between the effects of disorder and parallel field: the parallel field weakens…

Strongly Correlated Electrons · Physics 2007-05-23 V. M. Pudalov , G. Brunthaler , A. Prinz , G. Bauer

We report measurements of the zero-field resistivity in dilute 2D electron system in silicon at temperatures down to 35 mK. This extends the previously explored range of temperatures by almost an order of magnitude. On the metallic side,…

Strongly Correlated Electrons · Physics 2007-05-23 S. V. Kravchenko , T. M. Klapwijk

We consider transport of dilute two-dimensional electrons, with temperature between Fermi and Debye temperatures. In this regime, electrons form a nondegenerate plasma with mobility limited by potential disorder. Different kinds of…

Mesoscale and Nanoscale Physics · Physics 2009-06-11 D. S. Novikov

We report the results of an experimental study of the magnetoresistance $\rho_{xx}$ in two samples of $p$-Si/SiGe/Si with low carrier concentrations $p$=8.2$\times10^{10}$ cm$^{-2}$ and $p$=2$\times10^{11}$ cm$^{-2}$. The research was…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 I. L. Drichko , I. Yu. Smirnov , A. V. Suslov , O. A. Mironov , D. R. Leadley

We report a highly unusual temperature dependence in the magnetoresistance of a weakly interacting high mobility 2D electron gas (2DEG) under a parallel magnetic field and when the current is perpendicular to the field. While the linear…

Mesoscale and Nanoscale Physics · Physics 2012-02-06 Xiaoqing Zhou , B. Schmidt , L. W. Engel , G. Gervais , L. N. Pfeiffer , K. W. West , S. Das Sarma

Recent cold atom experiments have observed bad and strange metal behaviors in strongly-interacting Fermi-Hubbard systems. Motivated by these results, we calculate the thermoelectric transport properties of a 2D Fermi-Hubbard system in the…

Quantum Gases · Physics 2021-08-27 Thomas G. Kiely , Erich J. Mueller

Selfconsistent equations which describe the order parameter and chemical potential behaviour in $2D$ metalic system as functions of external magnetic field, $H$, temperature, $T$, and carrier density, $n$, are obtained. It is shown that for…

Condensed Matter · Physics 2019-08-15 V. P. Gusynin , V. M. Loktev , I. A. Shovkovy

When the electron density of highly crystalline thin films is tuned by chemical doping or ionic liq- uid gating, interesting effects appear including unconventional superconductivity, sizeable spin-orbit coupling, competition with…

Mesoscale and Nanoscale Physics · Physics 2018-12-19 G. Dezi , N. Scopigno , S. Caprara , M. Grilli

A theory is developed for the density and temperature dependent carrier conductivity in doped three-dimensional (3D) Dirac materials focusing on resistive scattering from screened Coulomb disorder due to random charged impurities (e.g.,…

Mesoscale and Nanoscale Physics · Physics 2015-01-20 S. Das Sarma , E. H. Hwang , Hongki Min

Observations are reported of a metal-insulator transition in a 2D hole gas in asymmetrically doped strained SiGe quantum wells. The metallic phase, which appears at low temperatures in these high mobility samples, is characterised by a…

Strongly Correlated Electrons · Physics 2009-10-30 P. T. Coleridge , R. L. Williams , Y. Feng , P. Zawadzki

We observe that in a strongly interacting two-dimensional electron system in ultra-clean SiGe/Si/SiGe quantum wells, the resistivity on the metallic side near the metal-insulator transition increases with decreasing temperature, reaches a…

We report temperature and density dependences of the spin susceptibility of strongly interacting electrons in Si inversion layers. We measured (i) the itinerant electron susceptibility $\chi^*$ from the Shubnikov-de Haas oscillations in…

Strongly Correlated Electrons · Physics 2018-10-09 V. M. Pudalov , A. Yu. Kuntsevich , M. E. Gershenson , I. S. Burmistrov , M. Reznikov

It is shown that recent experiments indicating a metal-insulator transition in 2D electron systems can be interpreted in terms of a simple model, in which the resistivity is controlled by scattering at charged hole traps located in the…

Disordered Systems and Neural Networks · Physics 2009-10-31 Boris L. Altshuler , Dmitrii L. Maslov

The apparent metal-insulator transition is observed in a high quality two-dimensional electron system (2DES) in the strained Si quantum well of a Si/Si_{1-x}Ge_x heterostructure with mobility \mu=1.9 x 10^5 cm^2/Vs at density n=1.45 x…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 K. Lai , W. Pan , D. C. Tsui , S. A. Lyon , M. Muhlberger , F. Schaffler

We study diffusive electron-electron interaction correction to conductivity by analyzing simultaneously $\rho_{xx}$ and $\rho_{xy}$ for disordered 2D electron systems in Si in tilted magnetic field. Tilting the field is shown to be a…

Mesoscale and Nanoscale Physics · Physics 2013-05-17 A. Yu. Kuntsevich , L. A. Morgun , V. M. Pudalov

Experiments on a constant-density two-dimensional hole system in a GaAs quantum well reveal that the metallic behavior observed in the zero-magnetic-field temperature dependence of the resistivity depends on the symmetry of the confinement…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 S. J. Papadakis , E. P. De Poortere , H. C. Manoharan , M. Shayegan , R. Winkler

We report direct experimental evidence that the insulating phase of a disordered, yet strongly interacting two-dimensional electron system (2DES) becomes unstable at low temperatures. As the temperature decreases, a transition from…

Mesoscale and Nanoscale Physics · Physics 2008-01-15 M. Baenninger , A. Ghosh , M. Pepper , H. E. Beere , I. Farrer , D. A. Ritchie