Charged fermions coupled to Ising gauge fields: Superfluidity confinement and emergent Dirac fermions

by Snir Gazit

at Condensed Matter Theory Seminar

Wed, 30 Nov 2016, 13:30
Physics building (#54) room 207

Abstract

Lattice gauge theories are ubiquitous in physics describing a wide range of phenomena from quark confinement to quantum materials At finite fermion density gauge theories are notoriously hard to analyze due to the fermion sign problem Here we investigate the Ising gauge theory in 2 1 dimensions a problem of great interest in condensed matter and show that it is free of the sign problem at arbitrary fermion density At generic filling we find that gauge fluctuations mediate pairing leading to a transition between a deconfined BCS state to a confined BEC At half filling a pi flux phase is generated spontaneously with emergent Dirac fermions The deconfined Dirac phase with a vanishing Fermi surface volume is a non trivial example of violation of Luttinger s theorem due to fractionalization At strong coupling we find a single continuous transition between the deconfined Dirac phase and the confined BEC in contrast to the expected split transition

Created on 26-11-2016 by Bar Lev, Yevgeny (ybarlev)
Updaded on 26-11-2016 by Bar Lev, Yevgeny (ybarlev)