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arXiv · 1604.03725

Dissipative Bose-Einstein condensation in contact with a thermal reservoir

Stephan Caspar·Florian Hebenstreit·David Mesterházy·Uwe-Jens Wiese
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Abstract

We investigate the real-time dynamics of open quantum spin-$1/2$ or hardcore boson systems on a spatial lattice, which are governed by a Markovian quantum master equation. We derive general conditions under which the hierarchy of correlation functions closes such that their time evolution can be computed semi-analytically. Expanding our previous work [Phys. Rev. A 93, 021602 (2016)] we demonstrate the universality of a purely dissipative quantum Markov process that drives the system of spin-$1/2$ particles into a totally symmetric superposition state, corresponding to a Bose-Einstein condensate of hardcore bosons. In particular, we show that the finite-size scaling behavior of the dissipative gap is independent of the chosen boundary conditions and the underlying lattice structure. In addition, we consider the effect of a uniform magnetic field as well as a coupling to a thermal bath to investigate the susceptibility of the engineered dissipative process to unitary and nonunitary perturbations. We establish the nonequilibrium steady-state phase diagram as a function of temperature and dissipative coupling strength. For a small number of particles $N$, we identify a parameter region in which the engineered symmetrizing dissipative process performs robustly, while in the thermodynamic limit $N\rightarrow \infty$, the coupling to the thermal bath destroys any long-range order.

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Stephan Caspar, Florian Hebenstreit, David Mesterházy, Uwe-Jens Wiese. 2016-07-07. Dissipative Bose-Einstein condensation in contact with a thermal reservoir. https://doi.org/10.1088/1367-2630%2F18%2F7%2F073015

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