title: Entanglement Entropy of the ν=1/2 Composite Fermion Non-Fermi Liquid State.
abstract: The so-called "non-Fermi liquid" behavior is very common in strongly correlated systems. However, its operational definition in terms of "what it is not" is a major obstacle for the theoretical understanding of this fascinating correlated state. Recently there has been much interest in entanglement entropy as a theoretical tool to study non-Fermi liquids. So far explicit calculations have been limited to models without direct experimental realizations. Here we focus on a two-dimensional electron fluid under magnetic field and filling fraction ν=1/2, which is believed to be a non-Fermi liquid state. Using a composite fermion wave function which captures the ν=1/2 state very accurately, we compute the second Rényi entropy using the variational Monte Carlo technique. We find the entanglement entropy scales as LlogL with the length of the boundary L as it does for free fermions, but has a prefactor twice that of free fermions.
authors.affiliation: Department of Physics, Binghamton University, Binghamton, New York 13902, USA.
authors.forename: Junping
authors.initials: J
authors.lastname: Shao
authors.affiliation: Department of Physics, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Eun-Ah
authors.initials: EA
authors.lastname: Kim
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: F D M
authors.initials: FD
authors.lastname: Haldane
authors.affiliation: Department of Physics, California State University Los Angeles, Los Angeles, California 90032, USA.
authors.forename: Edward H
authors.initials: EH
authors.lastname: Rezayi