Fock-space geometry and strong correlations in many-body localized systems

Abstract

We adopt a geometric perspective on Fock space to provide two complementary insights into the eigenstates in many-body-localized fermionic systems. On the one hand, individual many-bodylocalized eigenstates are well approximated by a Slater determinant of single-particle orbitals. On the other hand, the orbitals of different eigenstates in a given system display a varying, and generally imperfect, degree of compatibility, as we quantify by a measure based on the projectors onto the corresponding single-particle subspaces. We study this incompatibility between states of fixed and differing particle number, as well as inside and outside the many-body-localized regime. This gives detailed insights into the emergence and strongly correlated nature of quasiparticle-like excitations in many-body localized systems, revealing intricate correlations between states of different particle number down to the level of individual realizations.

9 pages, 5 figures

References in corpus (13)

• Many body localization and thermalization in quantum statistical mechanics
• Localization of interacting fermions at high temperature
• Many-body localization edge in the random-field Heisenberg chain
• Many body localization in Heisenberg XXZ magnet in a random field
• Phenomenology of fully many-body-localized systems
• Integrals of motion in the Many-Body localized phase
• Absence of diffusion in an interacting system of spinless fermions on a one-dimensional disordered lattice
• Ergodicity breaking in a model showing many-body localization
• Quantum-to-classical crossover of quasi-bound states in open quantum systems
• Dynamical model for the quantum-to-classical crossover of shot noise
• Fock-space anatomy of eigenstates across the many-body localisation transition
• Many-body localization of spinless fermions with attractive interactions in one dimension
• Scaling properties of a spatial one-particle density-matrix entropy in many-body localized systems