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arXiv · 1512.07093

Tilted optical lattices with defects as realizations of PT symmetry in Bose-Einstein condensates

Manuel Kreibich·Jörg Main·Holger Cartarius·Günter Wunner
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Abstract

A PT-symmetric Bose-Einstein condensate can theoretically be described using a complex optical potential, however, the experimental realization of such an optical potential describing the coherent in- and outcoupling of particles is a nontrivial task. We propose an experiment for a quantum mechanical realization of a PT-symmetric system, where the PT-symmetric currents are implemented by an accelerating Bose-Einstein condensate in a titled optical lattice. A defect consisting of two wells at the same energy level then acts as a PT-symmetric double-well if the tilt in the energy offsets of all further wells in the lattice is varied in time. We map the time-dependence of the amplitudes of a frozen Gaussian variational ansatz to a matrix model and increase the system size step by step starting with a six-well setup. In terms of this simple matrix model we derive conditions under which two wells of the Hermitian multi-well system behave exactly as the two wells of the PT-symmetric system.

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Manuel Kreibich, Jörg Main, Holger Cartarius, Günter Wunner. 2015-12-22. Tilted optical lattices with defects as realizations of PT symmetry in Bose-Einstein condensates. https://doi.org/10.1103/physreva.93.023624

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