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Density-functional calculations using an exact exchange potential for a two-dimensional electron gas (2DEG) formed in a GaAs single quantum well predict the existence of a spin-polarized phase, when an excited subband becomes slightly…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 A. R. Goñi , P. Giudici , F. A. Reboredo , C. R. Proetto , C. Thomsen , K. Eberl , M. Hauser

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

Two-dimensional (2D) ferroelectric semiconductors present opportunities for integrating ferroelectrics into high-density ultrathin nanoelectronics. Among the few synthesized 2D ferroelectrics, $\alpha$-In$_2$Se$_3$, known for its…

Materials Science · Physics 2024-02-29 Liyi Bai , Changming Ke , Zhongshen Luo , Tianyuan Zhu , Lu You , Shi Liu

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

A two-dimensional electron gas (2DEG) in two-valley semiconductors has two discrete degrees of freedom given by the spin and valley quantum numbers. We analyze the zero-temperature magnetic instabilities of two-valley semiconductors with…

Mesoscale and Nanoscale Physics · Physics 2021-01-11 Dmitry Miserev , Jelena Klinovaja , Daniel Loss

It has been puzzling that the resistivity of high mobility two-dimensional(2D) carrier systems in semiconductors with low carrier density often exhibits a large increase followed by a decrease when the temperature ($T$) is raised above a…

Strongly Correlated Electrons · Physics 2015-05-28 Richard L. J. Qiu , Xuan P. A. Gao , Loren N. Pfeiffer , Ken W. West

One of the main tasks in the investigation of 2-dimensional transition metal dichalcogenides is the determination of valley lifetimes. In this work, we combine time-resolved Kerr rotation with electrical transport measurements to explore…

An existence of predominant symmetrical spin configuration (spin polarised phase) and "diluted" density of states (pseudo-gap) in a layer under the Fermi level in a quantum wire is predicted. The condition of cross-over from non-polarised…

Strongly Correlated Electrons · Physics 2009-10-31 V. V'yurkov , A. Vetrov

Valleytronics is rapidly emerging as an exciting area of basic and applied research. In two dimensional systems, valley polarisation can dramatically modify physical properties through electron-electron interactions as demonstrated by such…

We show that the topology of the Fermi sea of a two-dimensional electron gas (2DEG) is reflected in the ballistic Landauer transport along a long and narrow Josephson $\pi$-junction that proximitizes the 2DEG. The low-energy Andreev states…

Mesoscale and Nanoscale Physics · Physics 2023-03-03 Pok Man Tam , Charles L. Kane

Ignited by the discovery of the metal-insulator transition, the behaviour of low-disorder two-dimensional (2D) electron systems is currently the focus of a great deal of attention. In the strongly-interacting limit, electrons are expected…

Strongly Correlated Electrons · Physics 2018-09-19 Pedro Brussarski , S. Li , S. V. Kravchenko , A. A. Shashkin , M. P. Sarachik

Valley, as a new degree of freedom for electrons, has drawn considerable attention due to its significant potential for encoding and storing information. Lifting the energy degeneracy to achieve valley polarization is necessary for…

Materials Science · Physics 2020-03-11 Pei Zhaos , Yandong Ma , Hao Wang , Baibiao Huang , Liangzhi Kou , Ying Dai

In recent years systematic experimental studies of the temperature dependence of the resistivity in a variety of dilute, ultra clean two dimensional electron/hole systems have revived the fundamental question of localization or,…

Disordered Systems and Neural Networks · Physics 2015-06-24 Alexander Punnoose , Alexander M. Finkel'stein

We report measurements of GaAs/AlGaAs undoped field-effect transistors in which two-dimensional electron gases (2DEGs) of exceptional quality and versatility are induced without modulation doping. Electron mobilities at T=4.2 K and density…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 G. R. Facer , B. E. Kane , A. S. Dzurak , R. J. Heron , N. E. Lumpkin , R. G. Clark , L. N. Pfeiffer , K. W. West

Spontaneous magnetization of a two-dimensional electron gas (2DEG) is discussed. It takes place for sufficiently high electron density (i.e. for a quantum fluid state) with $r_s<10$ which is quite beyond the condition of Wigner…

Strongly Correlated Electrons · Physics 2007-05-23 V. Vyurkov , A. Vetrov

Memory or transistor devices based on electron's spin rather than its charge degree of freedom offer certain distinct advantages and comprise a cornerstone of spintronics. Recent years have witnessed the emergence of a new field,…

Mesoscale and Nanoscale Physics · Physics 2021-09-13 Md. S. Hossain , M. K. Ma , K. A. Villegas Rosales , Y. J. Chung , L. N. Pfeiffer , K. W. West , K. W. Baldwin , M. Shayegan

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

Ferroelectricity in atomically thin bilayer structures has been recently predicted1 and measured[2-4] in two-dimensional (2D) materials with hexagonal non-centrosymmetric unit-cells. Interestingly, the crystal symmetry translates lateral…

We investigate electron transport along the surface of WTe$_2$ three-dimensional single crystals, which are characterized by coexistence of Weyl semimetal conductivity and ferroelectricity at room temperature. We find that non-linear…

Mesoscale and Nanoscale Physics · Physics 2022-12-16 N. N. Orlova , N. S. Ryshkov , A. V. Timonina , N. N. Kolesnikov , E. V. Deviatov

We theoretically study transport properties of a two-dimensional electron system on a hydrogen-passivated Si(111) surface in the field-effect-transistor (FET) configuration. We calculate the density and temperature dependent mobility and…

Materials Science · Physics 2009-11-11 E. H. Hwang , S. Das Sarma