Fock-space correlations and the origins of many-body localization

The authors approach the problem of many-body localization on the Fock space, with nodes and links representing many-body states and Hamiltonian matrix-elements. The problem maps exactly onto a tight-binding model on a complex high-dimensional graph with nontrivial correlated disorder. These correlations are shown to lie at the heart of many-body localization. The central result from this theory is that the correlations in the Fock-space disorder must be maximal for a many-body localized phase to be stable.