title: Absence of Disorder-Driven Metal-Insulator Transitions in Simple Holographic Models.
abstract: We study electrical transport in a strongly coupled strange metal in two spatial dimensions at finite temperature and charge density, holographically dual to the Einstein-Maxwell theory in an asymptotically four-dimensional anti-de Sitter space spacetime, with arbitrary spatial inhomogeneity, up to mild assumptions including emergent isotropy. In condensed matter, these are candidate models for exotic strange metals without long-lived quasiparticles. We prove that the electrical conductivity is bounded from below by a universal minimal conductance: the quantum critical conductivity of a clean, charge-neutral plasma. Beyond nonperturbatively justifying mean-field approximations to disorder, our work demonstrates the practicality of new hydrodynamic insight into holographic transport.
authors.affiliation: Instituut-Lorentz for Theoretical Physics, Leiden University, Niels Bohrweg 2, Leiden 2333 CA, Netherlands.
authors.forename: Sašo
authors.initials: S
authors.lastname: Grozdanov
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Lucas
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.|Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada.
authors.forename: Subir
authors.initials: S
authors.lastname: Sachdev
authors.affiliation: Instituut-Lorentz for Theoretical Physics, Leiden University, Niels Bohrweg 2, Leiden 2333 CA, Netherlands.
authors.forename: Koenraad
authors.initials: K
authors.lastname: Schalm