PIRSA:20020073

Deconfined metallic quantum criticality: a U(2) gauge theoretic approach

Zou, L. (2020). Deconfined metallic quantum criticality: a U(2) gauge theoretic approach. Perimeter Institute. https://pirsa.org/20020073

Zou, Liujun. Deconfined metallic quantum criticality: a U(2) gauge theoretic approach. Perimeter Institute, Feb. 18, 2020, https://pirsa.org/20020073 

          @misc{ pirsa_PIRSA:20020073,
            doi = {10.48660/20020073},
            url = {https://pirsa.org/20020073},
            author = {Zou, Liujun},
            keywords = {Condensed Matter},
            language = {en},
            title = {Deconfined metallic quantum criticality: a U(2) gauge theoretic approach},
            publisher = {Perimeter Institute},
            year = {2020},
            month = {feb},
            note = {PIRSA:20020073 see, \url{https://pirsa.org}}
          }

Liujun Zou

National University of Singapore

Talk number
PIRSA:20020073
Collection
Talk Type
Subject
Abstract

We discuss a new class of quantum phase transitions --- Deconfined Mott Transition (DMT) --- that describe a continuous transition between a Fermi liquid metal with a generic electronic Fermi surface and an insulator without emergent neutral Fermi surface. We construct a unified U(2) gauge theory to describe a variety of metallic and insulating phases, which include Fermi liquids, fractionalized Fermi liquids (FL*), conventional insulators and quantum spin liquids, as well as the quantum phase transitions between them. Using the DMT as a basic building block, we propose a distinct quantum phase transition --- Deconfined Metal-Metal Transition (DM2T) --- that describes a continuous transition between two metallic phases, accompanied by a jump in the size of their Fermi surfaces (also dubbed a 'Fermi transition'). We study these new classes of deconfined metallic quantum critical points using a renormalization group framework at the leading nontrivial order in a controlled double-expansion and comment on the various interesting scenarios that can emerge going beyond this leading order calculation.