TY - JOUR
T1 - The half-filled Landau level
T2 - The case for Dirac composite fermions
AU - Geraedts, Scott D.
AU - Zaletel, Michael P.
AU - Mong, Roger S.K.
AU - Metlitski, Max A.
AU - Vishwanath, Ashvin
AU - Motrunich, Olexei I.
N1 - Funding Information:
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.
PY - 2016/4/8
Y1 - 2016/4/8
N2 - 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 2kF 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.
AB - 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 2kF 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.
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U2 - 10.1126/science.aad4302
DO - 10.1126/science.aad4302
M3 - Article
C2 - 27124453
AN - SCOPUS:84963596005
SN - 0036-8075
VL - 352
SP - 197
EP - 201
JO - Science
JF - Science
IS - 6282
ER -