Out-of-equilibrium phase diagram of the quantum random energy model
Giulio Biroli, Davide Facoetti, Marco Schirò, Marco Tarzia, Pierpaolo Vivo
Abstract
The quantum version of Derrida's Random Energy model is the simplest model of a quantum glass. Here, the authors study its dynamical phase diagram, revealing the existence of three distinct dynamical phases: a many-body fully localized phase at low energy, an ergodic phase at high energy, and a multifractal ``bad metal'' phase at intermediate energy. In the latter, eigenfunctions occupy a diverging volume, yet an exponentially vanishing fraction of the total Hilbert space.
Topics & Concepts
Phase diagramErgodic theoryPhase spaceQuantumEigenfunctionStatistical physicsPhysicsMultifractal systemHilbert spacePhase (matter)Quantum mechanicsMathematicsPure mathematicsMathematical analysisEigenvalues and eigenvectorsFractalQuantum many-body systemsTheoretical and Computational PhysicsOpinion Dynamics and Social Influence