Ultracold Bosons with cavity-mediated long-range interactions: A local mean field analysis of the phase diagram
| Autor: | Heiko Rieger, A. E. Niederle, Giovanna Morigi |
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| Rok vydání: | 2016 |
| Předmět: |
Physics
Condensed Matter::Quantum Gases Quantum Physics Optical lattice Condensed matter physics Condensed Matter::Other Physics::Optics FOS: Physical sciences Quantum phases 01 natural sciences 010305 fluids & plasmas Superfluidity Supersolid Superglass Quantum Gases (cond-mat.quant-gas) 0103 physical sciences Condensed Matter - Quantum Gases 010306 general physics Quantum Physics (quant-ph) Charge density wave Phase diagram Boson |
| DOI: | 10.48550/arxiv.1606.00912 |
| Popis: | Ultracold bosonic atoms in optical lattices self-organize into a variety of structural and quantum phases when placed into a single-mode cavity and pumped by a laser. Cavity optomechanical effects induce an atom density modulation at the cavity-mode wave length that competes with the optical lattice arrangement. Simultaneously short-range interactions via particle hopping promote superfluid order, such that a variety of structural and quantum coherent phases can occur. We analyze the emerging phase diagram in two dimensions by means of an extended Bose-Hubbard model using a local mean field approach combined with a superfluid cluster analysis. For commensurate ratios of the cavity and external lattice wave lengths the Mott insulator-superfluid transition is modified by the appearance of charge density wave and supersolid phases, at which the atomic density supports the buildup of a cavity field. For incommensurate ratios, the optomechanical forces induce the formation of Bose-glass and superglass phases, namely non-superfluid and superfluid phases, respectively, displaying quasi-periodic density modulations, which in addition can exhibit structural and superfluid stripe formation. The onset of such structures is constrained by the onsite interaction and is favourable at fractional densities. Experimental observables are identified and discussed. Comment: 10 pages, 3 figures |
| Databáze: | OpenAIRE |
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