title: Characterizing disordered fermion systems using the momentum-space entanglement spectrum.
abstract: The use of quantum entanglement to study condensed matter systems has been flourishing in critical systems and topological phases. Additionally, using real-space entanglement one can characterize localized and delocalized phases of disordered fermion systems. Here we instead propose the momentum-space entanglement spectrum as a means of characterizing disordered models. We show that localization in one dimension can be characterized by the momentum space entanglement between left and right movers and illustrate our methods using explicit models with spatially correlated disorder that exhibit phases which avoid complete Anderson localization. The momentum space entanglement spectrum clearly reveals the location of delocalized states in the energy spectrum, can be used as a signature of the phase transition between a delocalized and localized phase, and only requires a single numerical diagonalization to yield clear results.
authors.affiliation: Department of Physics, University of Illinois, 1110 West Green Street, Urbana, Illinois 61801, USA.
authors.forename: Ian
authors.initials: I
authors.lastname: Mondragon-Shem
authors.affiliation: Department of Physics, University of Illinois, 1110 West Green Street, Urbana, Illinois 61801, USA.
authors.forename: Mayukh
authors.initials: M
authors.lastname: Khan
authors.affiliation: Department of Physics, University of Illinois, 1110 West Green Street, Urbana, Illinois 61801, USA.
authors.forename: Taylor L
authors.initials: TL
authors.lastname: Hughes