SKM 2023 – wissenschaftliches Programm
DY 48.1: Vortrag
Donnerstag, 30. März 2023, 15:00–15:15, MOL 213
Imperfect Many-Body Localization in Exchange-Disordered Isotropic Spin Chains — •Julian Siegl and John Schliemann — University of Regensburg
We study many-body localization in isotropic Heisenberg spin chains with the local exchange parameters being subject to quenched disorder. The Hamiltonian is invariant under global SU(2)- rotations and incorporates therefore a nonabelian symmetry. Systems of common spin length 1/2 and 1 are studied numerically using random matrix techniques. In both cases we find a transition from an ergodic phase at small disorder strength to an incompletely localized phase at stronger disorder. The transition is signaled by a maximum of the sample-to-sample variance of the averaged consecutive-gap ratio. The incompletely localized phase found here is distinguished from a fully localized system by the scaling behavior of the sample-to-sample variance.