Atom-light crystallization of BECs in multimode cavities: Nonequilibrium classical and quantum phase transitions, emergent lattices, supersolidity, and frustration
arXiv:1007.0922 · doi:10.1103/PhysRevA.82.043612
Abstract
The self-organization of a Bose-Einstein condensate in a transversely pumped optical cavity is a process akin to crystallization: when pumped by a laser of sufficient intensity, the coupled matter and light fields evolve, spontaneously, into a spatially modulated pattern, or crystal, whose lattice structure is dictated by the geometry of the cavity. In cavities having multiple degenerate modes, the quasi-continuum of possible lattice arrangements, and the continuous symmetry breaking associated with the adoption of a particular lattice arrangement, give rise to phenomena such as phonons, defects, and frustration, which have hitherto been unexplored in ultracold atomic settings involving neutral atoms. The present work develops a nonequilibrium field-theoretic approach to explore the self-organization of a BEC in a pumped, lossy optical cavity. We find that the transition is well described, in the regime of primary interest, by an effective equilibrium theory. At nonzero temperatures, the self-organization occurs via a fluctuation-driven first-order phase transition of the Brazovskii class; this transition persists to zero temperature, and crosses over into a quantum phase transition of a new universality class. We make further use of our field-theoretic description to investigate the role of nonequilibrium fluctuations on the self-organization transition, as well as to explore the nucleation of ordered-phase droplets, the nature and energetics of topological defects, supersolidity in the ordered phase, and the possibility of frustration controlled by the cavity geometry. In addition, we discuss the range of experimental parameters for which we expect the phenomena described here to be observable, along with possible schemes for detecting ordering and fluctuations via either atomic correlations or the correlations of the light emitted from the cavity.
34 pages, 13 figures; follow up to Nat. Phys. 5, 845 (2009)
References in corpus (15)
- Many-Body Physics with Ultracold Gases
- Cavity QED with a Bose-Einstein condensate
- Non-equilibrium quantum condensation in an incoherently pumped dissipative system
- Emergent superfluid crystals, frustration, and topologically defected states in multimode cavity QED
- Nonequilibrium quantum criticality in open electronic systems
- Self-organization of a Bose-Einstein condensate in an optical cavity
- Probing quantum phases of ultracold atoms in optical lattices by transmission spectra in cavity QED
- Mott insulator states of ultracold atoms in optical resonators
- Evidence for a Superglass State in Solid 4He
- Novel quantum phases of dipolar Bose gases in optical lattices
- Self-organization of atoms in a cavity field: threshold, bistability and scaling laws
- Mean field theory and fluctuation spectrum of a pumped, decaying Bose-Fermi system across the quantum condensation transition
- Phase-slip induced dissipation in an atomic Bose-Hubbard system
- Excess noise depletion of a Bose-Einstein condensate in an optical cavity
- Quenched Dislocation Enhanced Supersolid Ordering