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Related papers: Interaction Effects in Conductivity of a Two-Valle…

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The increase in the resistivity with decreasing temperature followed by a drop by more than one order of magnitude is observed on the metallic side near the zero-magnetic-field metal-insulator transition in a strongly interacting…

Measurements of conductance $G$ on short, wide, high-mobility Si-MOSFETs reveal both a two-dimensional metal-insulator transition (MIT) at moderate temperatures (1 $<~ T <$ 4~K) and mesoscopic fluctuations of the conductance at low…

Strongly Correlated Electrons · Physics 2009-10-30 K. P. Li , Dragana Popovic , S. Washburn

We investigated the magnetotransport in high quality ferromagnetic (Ga,Mn)As films and wires. At low temperature the conductivity decreases with decreasing temperature without saturation down to 20 mK. Here we show, that the conductivity…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Daniel Neumaier , Markus Schlapps , Ursula Wurstbauer , Janusz Sadowski , Matthias Reinwald , Werner Wegscheider , Dieter Weiss

We report measurements of the resistance of silicon MOSFETs as a function of temperature in high parallel magnetic fields where the 2D system of electrons has been shown to be fully spin-polarized. A magnetic field suppresses the metallic…

Strongly Correlated Electrons · Physics 2009-10-31 K. M. Mertes , Hairong Zheng , S. A. Vitkalov , M. P. Sarachik , T. M. Klapwijk

We report thermodynamic magnetization measurements of a 2-dimensional electron gas for several high mobility Si-MOSFETs. The low-temperature magnetization is shown to be strongly sub-linear function of the magnetic field. The susceptibility…

Strongly Correlated Electrons · Physics 2009-11-02 N. Teneh , A. Yu. Kuntsevich , V. M. Pudalov , T. M. Klapwijk , M. Reznikov

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 measurements of the temperature-dependent conductivity in a silicon metal-oxide-semiconductor field-effect transistor that contains sodium impurities in the oxide layer. We explain the variation of conductivity in terms of Coulomb…

Strongly Correlated Electrons · Physics 2007-05-23 T. Ferrus , R. George , C. H. W. Barnes , N. Lumpkin , D. J. Paul , M. Pepper

We report thermodynamic magnetization measurements of two-dimensional electrons in several high mobility Si metal-oxide-semiconductor field-effect transistors. We provide evidence for an easily polarizable electron state in a wide density…

Strongly Correlated Electrons · Physics 2012-11-29 N. Teneh , A. Yu. Kuntsevich , V. M. Pudalov , M. Reznikov

Two phenomena have been recently observed in high-mobility Si MOS structures: (1) strong enhancement of the metallic conduction at low temperatures, T < 2K, and (2) the scaling behavior of the temperature and electric field dependences of…

Strongly Correlated Electrons · Physics 2008-02-03 V. M. Pudalov

We demonstrate that the experimental data on the temperature dependence of the resistivity and conductivity for high-mobility Si-MOS structures, obtained for a wide range of densities (~ 1:7) at intermediate temperatures, agree…

Strongly Correlated Electrons · Physics 2007-05-23 V. M. Pudalov , M. E. Gershenson , H. Kojima , G. Brunthaler , G. Bauer

Low-field magnetotransport measurements on a high mobility (mu=110,000 cm^2/Vs) two-dimensional (2D) electron system on a H-terminated Si(111) surface reveal a sixfold valley degeneracy with a valley splitting <= 0.1 K. The zero-field…

Mesoscale and Nanoscale Physics · Physics 2009-10-26 Robert N. McFarland , Tomasz M. Kott , Luyan Sun , K. Eng , B. E. Kane

We show that the recent experimental claim [Pudalov {\it et al}. \prl {\bf 91}, 126403 (2003) ] of observing ``interaction effects in the conductivity of Si inversion layers at intermediate temperatures'' is incorrect and misleading. In…

Strongly Correlated Electrons · Physics 2009-11-10 S. Das Sarma , E. H. Hwang

The 2-D electron system (2DES) in Si metal-oxide field-effect transistors (MOSFETS) consists of two distinct electron fluids interacting with each other. We calculate the total energy as a function of the density $n$, and the spin…

Strongly Correlated Electrons · Physics 2007-05-23 M. W. C. Dharma-wardana , François Perrot

The 2D semimetal consisting of heavy holes and light electrons is studied. The consideration is based on assumption that electrons are quantized by magnetic field while holes remain classical. We assume also that the interaction between…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 M. V. Entin , L. I. Magarill

We analyze here the behavior near the 2D insulator-superconductor quantum critical point in the presence of a perpendicular magnetic field. We show that with increasing field $H$, the quantum disordered and quantum critical regimes, in…

Condensed Matter · Physics 2009-11-07 Denis Dalidovich , Philip Phillips

We report experiment and theory on an ambipolar gate-controlled Si-vacuum field effect transistor (FET) where we study electron and hole (low-temperature 2D) transport in the same device simply by changing the external gate voltage to tune…

Mesoscale and Nanoscale Physics · Physics 2015-08-04 Binhui Hu , M. M. Yazdanpanah , B. E. Kane , E. H. Hwang , S. Das Sarma

Recent thermodynamic measurements on two-dimensional (2D) electron systems have found diverging behavior in the magnetic susceptibility and appearance of ferromagnetism with decreasing electron density. The critical densities for these…

Strongly Correlated Electrons · Physics 2007-05-23 S. M. Fazeli , K. Esfarjani , B. Tanatar

By analyzing the temperature ($T$) and density ($n$) dependence of the measured conductivity ($\sigma$) of 2D electrons in the low density ($\sim10^{11}$cm$^{-2}$) and temperature (0.02 - 10 K) regime of high-mobility (1.0 and 1.5 $\times…

Mesoscale and Nanoscale Physics · Physics 2009-07-21 L. A. Tracy , E. H. Hwang , K. Eng , G. A. Ten Eyck , E. P. Nordberg , K. Childs , M. S. Carroll , M. P. Lilly , S. Das Sarma

In a recent Letter, Kravchenko et al. [cond-mat/9608101] have provided evidence for a metal-insulator transition (MIT) in a two-dimensional electron system (2DES) in Si metal-oxide-semiconductor field-effect transistors (MOSFETs). The…

Strongly Correlated Electrons · Physics 2008-02-03 K. Ismail , J. O. Chu , Dragana Popovic , A. B. Fowler , S. Washburn

In this work we present the results of theoretical analysis of the de Haas-van Alphen oscillations in quasi-two-dimensional conductors. We have been studying the effect of the Fermi-liquid correlations of charge carriers on the above…

Materials Science · Physics 2008-10-28 Natalya A. Zimbovskaya