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Related papers: An experimental study on $\Gamma$(2) modular symme…

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We report a magnetotransport study of the termination of the spin-resolved integer quantum Hall effect by controlled disorder in a gated GaAs/AlGaAs heterostructure. We have found that, for a given N^{th} Landau level, the difference in…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 L. W. Wong , H. W. Jiang , E. Palm , W. J. Schaff

The average electron spin-polarization $\cal P$ of two-dimensional electron gas confined in $\rm GaAs/GaAlAs$ multiple quantum-wells was measured by nuclear magnetic resonance (NMR) near the fractional quantum Hall state with filling factor…

Mesoscale and Nanoscale Physics · Physics 2019-08-17 N. Freytag , Y. Tokunaga , M. Horvatic , C. Berthier , M. Shayegan , L. Levy

We study a (1+1)-dimensional quantum circuit consisting of Haar-random unitary gates and projective measurements that conserve a total $U(1)$ charge and thus have $U(1)$ symmetry. In addition to a measurement-induced entanglement transition…

Disordered Systems and Neural Networks · Physics 2023-01-31 Hisanori Oshima , Yohei Fuji

Low-energy transport measurements in Quantum Hall systems have been argued to be governed by emergent modular symmetries whose predictions are robust against many of the detailed microscopic dynamics. We propose the recently-observed…

Mesoscale and Nanoscale Physics · Physics 2008-11-26 C. P. Burgess , B. P. Dolan

We show that, for the transition between any two quantum Hall states, the semi-circle law and the existence of a duality symmetry follow solely from the consistency of the law of corresponding states with the two-dimensional scaling flow.…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 C. P. Burgess , Rim Dib , Brian P. Dolan

In a GaAs/AlGaAs two-dimensional electron system with two occupied subbands, the experimentally determined phase diagram in the density-magnetic field plane exhibits rich topological features. Ring-like structures are observed at even…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 X. C. Zhang , D. R. Faulhaber , H. W. Jiang

We measure the chemical potential jump across the fractional gap in the low-temperature limit in the two-dimensional electron system of GaAs/AlGaAs single heterojunctions. In the fully spin-polarized regime, the gap for filling factor…

Strongly Correlated Electrons · Physics 2007-09-03 V. S. Khrapai , A. A. Shashkin , M. G. Trokina , V. T. Dolgopolov , V. Pellegrini , F. Beltram , G. Biasiol , L. Sorba

Using a combination of heat pulse and nuclear magnetic resonance techniques we demonstrate that the phase boundary separating the interlayer phase coherent quantum Hall effect at $\nu_T = 1$ in bilayer electron gases from the weakly coupled…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 I. B. Spielman , L. A. Tracy , J. P. Eisenstein , L. N. Pfeiffer , K. W. West

Until the late 1980s, phases of matter were understood in terms of Landau's symmetry breaking theory. Following the discovery of the quantum Hall effect the introduction of a second class of phases, those with topological order, was…

Strongly Correlated Electrons · Physics 2016-03-09 N. Samkharadze , K. A. Schreiber , G. C. Gardner , M. J. Manfra , E. Fradkin , G. A. Csáthy

Two dimensional inversion symmetry ($180^{\circ}$ rotations in the ``Hall plane'' that hosts the incompressible electron fluid that exhibits the quantized Hall effect) is identified as its fundamental unbroken symmetry. A consequence is…

Mesoscale and Nanoscale Physics · Physics 2023-02-23 F. D. M. Haldane

An analytic form for the conductivity tensor in crossover between two quantum Hall plateaux is derived, which appears to be in good agreement with existing experimental data. The derivation relies on an assumed symmetry between quantum Hall…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 Brian P. Dolan

We analyze the bilayer quantum Hall (QH) system by mapping it to the monolayer QH system with spin degrees of freedom. By this mapping the tunneling interaction term is identified with the Zeeman term. We clarify the mechanism of a…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Z. F. Ezawa

Magnetic-field-induced phase transitions in the integer quantum Hall effect are studied under the formation of paired Landau bands arising from Zeeman spin splitting. By investigating features of modular symmetry, we showed that…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 D. R. Hang , R. B. Dunford , Gil-Ho Kim , H. D. Yeh , C. F. Huang , D. A. Ritchie , I. Farrer , Y. W. Zhang , C. -T. Liang , Y. H. Chang

We propose a quantum stripe (smectic) coupled-Luttinger-liquid model for the anisotropic states which occur in two-dimensional electron systems with high-index partial Landau level filling, $\nu^{*} = \nu - \lbrack\nu\rbrack$. Perturbative…

Condensed Matter · Physics 2009-10-31 A. H. MacDonald , Matthew P. A. Fisher

Gated GaAs/AlGaAs heterostructures were used to determine the low-temperature behavior of the two-dimensional electron gas near filling factor nu=1/2 in the disorder-magnetic-field plane. We identify a line on which sigma_{xy} is…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 L. W. Wong , H. W. Jiang , W. J. Schaff

We consider Coulomb drag between two layers of two-dimensional electron gases subject to a strong magnetic field, with the Landau level filling factor in each layer being 1/2. We find $\rho_D$ to be very large, as compared to the zero…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Ady Stern , Iddo Ussishkin

We report new experimental data on the plateau-insulator transition in the quantum Hall regime, taken from a low mobility InGaAs/InP heterostructure. By employing the fundamental symmetries of the quantum transport problem we are able to…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 A. M. M. Pruisken , D. T. N. de Lang , L. A. Ponomarenko , A. de Visser

We have measured the temperature dependence of the conductivity $\sigma_{xx}$ of a two-dimensional electron system deep into the localized regime of the quantum Hall plateau transition. Using variable-range hopping theory we are able to…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 F. Hohls , U. Zeitler , R. J. Haug

We study the critical spin-polarization energy ($\alpha_{\rm C}$) above which fractional quantum Hall states in two-dimensional electron systems confined to symmetric GaAs quantum wells become fully spin-polarized. We find a significant…

Mesoscale and Nanoscale Physics · Physics 2014-09-23 Yang Liu , S. Hasdemir , A. Wójs , J. K. Jain , L. N. Pfeiffer , K. W. West , K. W. Baldwin , M. Shayegan

Spin-orbit coupling in semiconductors relates the spin of an electron to its momentum and provides a pathway for electrically initializing and manipulating electron spins for applications in spintronics and spin-based quantum information…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 V. Sih , R. C. Myers , Y. K. Kato , W. H. Lau , A. C. Gossard , D. D. Awschalom