Hannover 2016 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 19: Ultracold Atoms, Ions and Molecules III (with A)
Q 19.8: Talk
Tuesday, March 1, 2016, 12:45–13:00, f342
Multicritical behaviour in dissipative Ising models — •Vincent Overbeck1, Mohammad Maghrebi2, Alexey Gorshkov2, and Hendrik Weimer1 — 1Institut für Theoretische Physik, Leibniz Universität Hannover, Deutschland — 2Joint Quantum Institute, NIST/University of Maryland, College Park, MD, USA
Stationary states of dissipative quantum many-body systems are of great interest, having the possibility to undergo dissipative phase transitions that are fundamentally different from thermal equilibrium. We consider a dissipative extension of the Ising model, where the dissipation preserves the Z2 symmetry. Using a variational approach [1,2], we find a second order and a first order phase transition line, which meet at a multicritical point that is not found in the equilibrium case. We make an analysis of the full phase diagram, discussing in detail the role of fluctuations in this model. Finally, we present a possible experimental realization based on Rydberg-dressed spin interactions.
[1] H. Weimer, Variational Principle for Steady States of Dissipative Quantum Many-Body Systems, Phys. Rev. Lett. 114, 040402 (2015).
[2] H. Weimer, Variational analysis of driven-dissipative Rydberg gases, Phys. Rev. A 91, 063401 (2015).