Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

DY: Fachverband Dynamik und Statistische Physik

DY 6: Dynamics in many-body systems: Equilibration and localization I (joint session DY/TT)

DY 6.8: Vortrag

Montag, 1. April 2019, 12:00–12:15, H19

Many-body localization and delocalization in large quantum chains — •Elmer V. H. Doggen¹, Frank Schindler², Konstantin S. Tikhonov^1,3, Alexander D. Mirlin^1,3,4,5, Titus Neupert², Dmitry G. Polyakov¹, and Igor V. Gornyi^1,3,4,6 — ¹Institut für Nanotechnologie, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany — ²Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland — ³L. D. Landau Institute for Theoretical Physics RAS, 119334 Moscow, Russia — ⁴Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany — ⁵Petersburg Nuclear Physics Institute, 188300 St. Petersburg, Russia — ⁶A. F. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia

We theoretically study the quench dynamics for an isolated Heisenberg spin chain with a random on-site magnetic field, which is one of the paradigmatic models of a many-body localization transition. We use the time-dependent variational principle as applied to matrix product states, which allows us to controllably study chains of a length up to L=100 spins. We find that the consideration of the larger system sizes substantially increases the estimate for the critical disorder that separates the ergodic and many-body localized regimes, compared to the values in the literature. From a technical perspective, we develop an adaptation of the ``learning by confusion'' machine-learning approach that can determine the critical disorder.