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The half-filled Landau level: the case for Dirac composite fermions

Geraedts, Scott D. and Zaletel, Michael P. and Mong, Roger S. K. and Metlitski, Max A. and Vishwanath, Ashvin and Motrunich, Olexei I. (2016) The half-filled Landau level: the case for Dirac composite fermions. Science, 352 (6282). pp. 197-201. ISSN 0036-8075. doi:10.1126/science.aad4302.

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In a two-dimensional electron gas under a strong magnetic field, correlations generate emergent excitations distinct from electrons. It has been predicted that “composite fermions”—bound states of an electron with two magnetic flux quanta—can experience zero net magnetic field and form a Fermi sea. Using infinite-cylinder density matrix renormalization group numerical simulations, we verify the existence of this exotic Fermi sea, but find that the phase exhibits particle-hole symmetry. This is self-consistent only if composite fermions are massless Dirac particles, similar to the surface of a topological insulator. Exploiting this analogy, we observe the suppression of 2k_F backscattering, a characteristic of Dirac particles. Thus, the phenomenology of Dirac fermions is also relevant to two-dimensional electron gases in the quantum Hall regime.

Item Type:Article
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URLURL TypeDescription Paper
Motrunich, Olexei I.0000-0001-8031-0022
Additional Information:© 2016 American Association for the Advancement of Science. Received 15 September 2015; accepted 16 February 2016. We enjoyed conversations with M. Barkeshli, M. Fisher, D. Haldane, R. Mishmash, C. Nayak, N. Read, E. Rezayi, D. Son, and T. Senthil. We particularly thank M. Barkeshli for first bringing the enigma of PH symmetry to our attention. R.M. and A.V. acknowledge KITP for hospitality. Supported by the National Science Engineering Research Council of Canada and U.S. Department of Energy BES grant de-sc0002140 (S.G.), the Sherman Fairchild Foundation (R.M.), U.S. Army Research Office grant W911NF-14-1-0379 (M.M.), a Simons Investigator Award (A.V.), NSF grant PHY11-25915 (R.M. and A.V.), NSF grant DMR 1206096 (S.G. and O.I.M.), and the Caltech Institute for Quantum Information and Matter, an NSF Physics Frontiers Center with support of the Gordon and Betty Moore Foundation. During the completion of this work, reference (53) appeared, which also provides a theoretical discussion of the PH-symmetric CFL.
Group:Institute for Quantum Information and Matter
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Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Department of Energy (DOE)DE-SC0002140
Sherman Fairchild FoundationUNSPECIFIED
Army Research Office (ARO)W911NF-14-1-0379
Simons FoundationUNSPECIFIED
Institute for Quantum Information and Matter (IQIM)UNSPECIFIED
NSF Physics Frontiers CenterUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Issue or Number:6282
Record Number:CaltechAUTHORS:20160404-074621321
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Official Citation:The half-filled Landau level: The case for Dirac composite fermions By Scott D. Geraedts, Michael P. Zaletel, Roger S. K. Mong, Max A. Metlitski, Ashvin Vishwanath, Olexei I. Motrunich Science 08 Apr 2016 : 197-201
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:65872
Deposited By: Ruth Sustaita
Deposited On:04 Apr 2016 19:10
Last Modified:10 Nov 2021 23:50

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