Many-body delocalization in a strongly disordered system with long-range interactions: Finite-size scaling

Many-body localization in a disordered system of interacting spins coupled by the long-range interaction 1/R^α is investigated combining analytical theory considering resonant interactions and a finite-size scaling of exact numerical solutions with number of spins N. The numerical results for a one-dimensional system are consistent with the general expectations of analytical theory for a d-dimensional system including the absence of localization in the infinite system at α<2d and a universal scaling of a critical energy disordering Wc∝N^2d-αd.