Regensburg 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 4: Dynamics in many-body systems: Equilibriation and localization
(Joint session of DY and TT organized by DY)
TT 4.6: Vortrag
Montag, 7. März 2016, 10:45–11:00, H47
Fluctuations, meta-stability and symmetry-breaking in open many-body systems — •Henrik Wilming1, Albert H. Werner1, Jens Eisert1, and Michael J. Kastoryano2 — 1Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany — 2NBIA, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, DK
It is known that finite fluctuations of densities in thermal states correspond to the existence of several phases. In the case of fluctuations in order-parameters, they lead to the existence of spontaneous symmetry-breaking. Such results are purely kinematic in that they do not show how these states are prepared by nature.
Here, we consider the corresponding dynamical question: We assume that a state with finite fluctuations in a density is prepared by a dissipative Markovian short-range dynamics that is in detailed balance and show that such dynamics necessarily also has different meta-stable states, which converge to steady-states on (quasi-)local observables in the thermodynamic limit. In the case of fluctuating order-parameters we show the existence of explicitly symmetry-breaking meta-stable states and construct dissipative Goldstone-modes on top of them.
The existence of such meta-stable states shows that it is inherently difficult to prepare a many-body state with strong long-range correlations by short-range dissipative processes fulfilling detailed balance. Our results hold on regular lattices in arbitrary spatial dimensions and are constructive in the sense that we explicitly write down the meta-stable states.