Dynamics of spatial phase coherence in a dissipative Bose-Hubbard atomic system
| Autor: | Vatré, Rémy, Bouganne, Raphaël, Aguilera, Manel Bosch, Ghermaoui, Alexis, Beugnon, Jérôme, Lopes, Raphael, Gerbier, Fabrice |
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| Rok vydání: | 2024 |
| Předmět: | |
| Zdroj: | Comptes Rendus. Physique, Online first (2023), pp. 1-22 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.5802/crphys.166 |
| Popis: | We investigate the loss of spatial coherence of one-dimensional bosonic gases in optical lattices illuminated by a near-resonant excitation laser. Because the atoms recoil in a random direction after each spontaneous emission, the atomic momentum distribution progressively broadens. Equivalently, the spatial correlation function (the Fourier-conjugate quantity of the momentum distribution) progressively narrows down as more photons are scattered. Here we measure the correlation function of the matter field for fixed distances corresponding to nearest-neighbor (n-n) and next-nearest-neighbor (n-n-n) sites of the optical lattice as a function of time, hereafter called n-n and n-n-n correlators. For strongly interacting lattice gases, we find that the n-n correlator $C_1$ decays as a power-law at long times, $C_1\propto 1/t^{\alpha}$, in stark contrast with the exponential decay expected for independent particles. The power-law decay reflects a non-trivial dissipative many-body dynamics, where interactions change drastically the interplay between fluorescence destroying spatial coherence, and coherent tunnelling between neighboring sites restoring spatial coherence at short distances. The observed decay exponent $\alpha \approx 0.54(6) $ is in good agreement with the prediction $\alpha=1/2$ from a dissipative Bose-Hubbard model accounting for the fluorescence-induced decoherence. Furthermore, we find that the n-n correlator $C_1$ controls the n-n-n correlator $C_2$ through the relation $C_2 \approx C_1^2$, also in accordance with the dissipative Bose-Hubbard model. Comment: published in the special issue of Comptes Rendus Physique dedicated to Jean Dalibard's CNRS Gold Medal. Details of calculations, included as an appendix in the published article, are available in the ancillary file |
| Databáze: | arXiv |
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