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Related papers: Next-level composite fermions

200 papers

We report on an observation of a fractional quantum Hall effect in an ultra-high quality two-dimensional hole gas hosted in a strained Ge quantum well. The Hall resistance reveals precisely quantized plateaus and vanishing longitudinal…

Mesoscale and Nanoscale Physics · Physics 2015-11-18 Q. Shi , M. A. Zudov , C. Morrison , M. Myronov

We report the observation of a new fractional quantum Hall state in the second Landau level of a two-dimensional electron gas at the Landau level filling factor $\nu=2+6/13$. We find that the model of noninteracting composite fermions can…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 A. Kumar , M. J. Manfra , G. A. Csáthy , L. N. Pfeiffer , K. W. West

We study the properties of rotating Bose-Einstein condensates in parabolic traps, with coherence length large compared to the system size. In this limit, it has been shown that unusual groundstates form which cannot be understood within a…

Condensed Matter · Physics 2009-10-31 N. R. Cooper , N. K. Wilkin

A symmetrically doped double layer electron system with total filling fraction $\nu=1/m$ decouples into two even denominator ($\nu=1/2 m$) composite fermion `metals' when the layer spacing is large. Out-of-phase fluctuations of the…

Condensed Matter · Physics 2009-10-28 N. E. Bonesteel , I. A. McDonald , C. Nayak

The Lowest Landau Level (LLL), long distance theory of Composite Fermions (CF) developed by Murthy and myself is minimally extended to all distances, guided by very general principles. The resulting theory is mathematically consistent, and…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 R. Shankar

We investigate the spectrum of interacting electrons at arbitrary filling factors in the limit of vanishing Zeeman splitting. The composite fermion theory successfully explains the low-energy spectrum {\em provided the composite fermions…

Condensed Matter · Physics 2009-10-22 X. G. Wu , J. K. Jain

Graphene is a two-dimensional carbon material with a honeycomb lattice and Dirac-like low-energy excitations. When Zeeman and spin-orbit interactions are neglected its Landau levels are four-fold degenerate, explaining the $4 e^2/h$…

Mesoscale and Nanoscale Physics · Physics 2008-06-30 Kentaro Nomura , A. H. MacDonald

Even-denominator fractional quantum Hall states are promising candidates for fault-tolerant quantum computing due to their underlying non-Abelian topological orders. However, the topological order of these states remains hotly debated.…

Correlations between particles can lead to subtle and sometimes counterintuitive phenomena. We analyze one such case, occurring during the sudden expansion of fermions in a lattice when the initial state has a strong admixture of double…

Quantum Gases · Physics 2009-10-20 F. Heidrich-Meisner , S. R. Manmana , M. Rigol , A. Muramatsu , A. E. Feiguin , E. Dagotto

We study the quantum Hall states that appear in the dilute limit of rotating ultracold fermionic gases when a single hyperfine species is present. We show that the p-wave scattering translates into a pure hard-core interaction in the lowest…

Other Condensed Matter · Physics 2009-11-10 Thierry Jolicoeur , Nicolas Regnault

The current state of the theory of the Fractional Quantum Hall Effect is critically analyzed, especially the generally accepted concept of composite fermions. It is argued that there is no sound theoretical foundation for this concept. A…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. I. Dyakonov

Owing to the spin, valley, and orbital symmetries, the lowest Landau level (LL) in bilayer graphene exhibits multicomponent quantum Hall ferromagnetism. Using transport spectroscopy, we investigate the energy gaps of integer and fractional…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 Yanmeng Shi , Yongjin Lee , Shi Che , Ziqi Pi , Timothy Espiritu , Petr Stepanov , Dmitry Smirnov , Chun Ning Lau , Fan Zhang

The fractional quantum Hall effect is a very particular manifestation of electronic correlations in two-dimensional systems in a strong perpendicular magnetic field. It arises as a consequence of a strong Coulomb repulsion between electrons…

Mesoscale and Nanoscale Physics · Physics 2022-07-08 Mark O. Goerbig

In the limit of very fast rotation atomic Bose-Einstein condensates may reside entirely in the lowest two-dimensional Landau level (LLL). For small enough filling factor of the LLL, one may have formation of fractional quantum Hall states.…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Brice Chung , Thierry Jolicoeur

Effective mass of the composite fermion in the fractional quantum Hall system, which is of purely interaction originated, is shown, from a numerical study, to exhibit a curious nonmonotonic behavior with a staircase correlated with the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Masaru Onoda , Takahiro Mizusaki , Hideo Aoki

Composite fermion metal states emerge in quantum Hall bilayers at total Landau level filling factor $\nu_T$=1 when the tunneling gap collapses by application of in-plane components of the external magnetic field. Evidence of this…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Biswajit Karmakar , Stefano Luin , Vittorio Pellegrini , Aron Pinczuk , Brian S. Dennis , Loren N. Pfeiffer , Ken W. West

Via measurements of commensurability features near Landau filling factor $\nu=1/2$, we probe the shape of the Fermi contour for hole-flux composite fermions confined to a wide GaAs quantum well. The data reveal that the composite fermions…

Mesoscale and Nanoscale Physics · Physics 2015-05-04 M. A. Mueed , D. Kamburov , Yang Liu , M. Shayegan , L. N. Pfeiffer , K. W. West , K. W. Baldwin , R. Winkler

In a GaAs/AlGaAs quantum well of electron density 1x10^{11} cm^{-2} we observe a fractional quantum Hall effect (FQHE) at filling factors nu=4/11, and 5/13, and weaker states at nu=6/17, 4/13, 5/17 and 7/11. These sequences of fractions do…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 W. Pan , H. L. Stormer , D. C. Tsui , L. N. Pfeiffer , K. W. Baldwin , K. W. West

Evidence for developing fractional quantum Hall effect (FQHE) at filling fraction $\nu{=}1/6$ and $1/8$ has recently been reported in wide GaAs quantum wells [Wang \emph{et al.}, PRL {\bf 134}, 046502 (2025)]. In this article, we…

Strongly Correlated Electrons · Physics 2025-07-09 Ajit C. Balram , Anirban Sharma , J. K. Jain

Jinwu Ye has shown that two flux quanta are attached in one layer while the electron is in the other layer to form a mutually composite fermion (MCF). This idea is based on an earlier idea that CF are formed by attaching two flux quanta to…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Keshav N. Shrivastava