Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 81: Nonequilibrium Quantum Many-Body Systems III

TT 81.5: Vortrag

Donnerstag, 15. März 2018, 10:30–10:45, H 3010

Boundary-driven Heisenberg chain in the long-range interacting regime: Robustness against far-from-equilibrium effects — Leon Droenner and •Alexander Carmele — Technische Universität Berlin, Institut für Theoretische Physik, Hardenbergstr. 36, 10623 Berlin

The discovery of disorder induced localization in the presence of interactions,known as many-body localization, opened a new field of theoretical and experimental investigations. A common generic model to study such effects is the disordered isotropic Heisenberg spin-chain [1]. By applying two magnetic boundary reservoirs, we drive the system out of equilibrium and induce a nonzero steady-state current [2]. The long-range coupled chain shows nearly ballistic transport and linear response for all potential differences of the external reservoirs. In contrast, the common isotropic nearest-neighbor coupling shows negative differential conductivity and a transition from diffusive to subdiffusive transport for a far-from-equilibrium driving. We find for the disordered long-range coupled XXZ chain, any change in the transport behavior is independent of the potential difference and the coupling strengths of the external reservoirs [2]. Therefore, to distinguish many-body localization as an effect of disorder from the spin-blockade, long-range coupling provides a clear understanding of MBL for boundary-driven systems as it is robust against far-from-equilibrium effects.

[1] M. Znidaric et al, Phys. Rev. Lett. 117, 040601 (2016).

[2] L. Droenner and A. Carmele Phys. Rev. B 96, 184421 (2017).