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arXiv · 1311.5393

Bose-Einstein Condensation and Many-Body Localization of Rotational Excitations of Polar Molecules

M. P. Kwasigroch·N. R. Cooper
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Abstract

We study theoretically the collective dynamics of rotational excitations of polar molecules loaded into an optical lattice in two dimensions. These excitations behave as hard-core bosons with a relativistic energy dispersion arising from the dipolar coupling between molecules. This has interesting consequences for the collective many-body phases. The rotational excitations can form a Bose-Einstein condensate at non-zero temperature, manifesting itself as a divergent $T_2$ coherence time of the rotational transition even in the presence of inhomogeneous broadening. The dynamical evolution of a dense gas of rotational excitations shows regimes of non-ergodicity, characteristic of many-body localization and localization protected quantum order.

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M. P. Kwasigroch, N. R. Cooper. 2013-11-21. Bose-Einstein Condensation and Many-Body Localization of Rotational Excitations of Polar Molecules. https://doi.org/10.1103/physreva.90.021605

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