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DY: Fachverband Dynamik und Statistische Physik
DY 12: Quantum Dynamics, Decoherence, and Quantum Information II
DY 12.5: Talk
Tuesday, March 15, 2011, 11:15–11:30, ZEU 255
Dynamics of quantum phase transitions using ensembles of classical trajectories — •Alexander Itin1,2 and Peter Schmelcher1 — 1Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany — 2Space Research Institute, Profsoyuznaya str. 84/32, Moscow 117997, Russia
Recently, Truncated Wigner Approximation was applied to study dynamics of quantum phase transitions (QPT) in infinitely-coordinated models such as the Dicke and Lipkin-Meshkov-Glick models [1,2,3]. The initial quantum state is represented by an ensemble of classical trajectories, with quantum observables being obtained by averaging over the classical ensemble. As an external parameter is changed, the quantum system experiences a passage through a QPT, while trajectories from the classical ensemble undergo a passage through a bifurcation. Non-adiabaticity of the ensemble of classical trajectories can be described by mapping to Painleve equations, as shown recently in [2,3]. After overviewing recent results in this field, we present the application of the method to the dynamics of splitting and merging of multiple Bose-Einstein condensates [4,5].
[1] A. Altland et al., Phys.Rev,A 79, 042703 (2009).
[2] A.P. Itin and P. Törmä, Phys. Rev. A 79, 055602 (2009).
[3] A.P. Itin and P. Törmä, arXiv:0901.4778.
[4] J. Dziarmaga et al., Phys. Rev. Lett. 101, 115701 (2008)
[5] R. Schützhold et al., Phys. Rev. Lett. 97, 200601 (2006)