Dicke quantum phase transition with a superfluid gas in an optical cavity

By K. Baumann, C. Guerlin, Ferdinand Brennecke, Tilman Esslinger. Nature, 2009

1,289 citations recorded by the source corpus.

A phase transition describes the sudden change of state of a physical system, such as melting or freezing. Quantum gases provide the opportunity to establish a direct link between experiments and generic models that capture the underlying physics. The Dicke model describes a collective matter–light interaction and has been predicted to show an intriguing quantum phase transition. Here we realize the Dicke quantum phase transition in an open system formed by a Bose–Einstein condensate coupled to an optical cavity, and observe the emergence of a self-organized supersolid phase. The phase transition is driven by infinitely long-range interactions between the condensed atoms, induced by two-photon processes involving the cavity mode and a pump field. We show that the phase transition is described by the Dicke Hamiltonian, including counter-rotating coupling terms, and that the supersolid phase is associated with a spontaneously broken spatial symmetry. The boundary of the phase transition is mapped out in quantitative agreement with the Dicke model. Our results should facilitate studies of quantum gases with long-range interactions and provide access to novel quantum phases.

Subfields: Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/74f1e30c609da83bfa49112172afae6adbe90aaa

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

Citations in the corpus

Cluster mean-field approach to the steady-state phase diagram of dissipative spin systems (2016, result): “This vanishing order at strong coupling is similar to the absence of ordering on resonance in the Dicke model [12] and the suppression of ordering in the degenerate limit of the Rabi model [24].”
Keldysh field theory for driven open quantum systems (2015, background): “Strong motivation for the exploration of non-thermal stationary states comes from a recent surge of experiments in diverse areas: in cold atomic gases [6– 8], hybrid light-matter systems of Bose-Einstein condensates placed in optical cavities are created [9, 10], or driven Rydberg ensembles are prep”
Nonequilibrium phase transition in a spin-1 Dicke model (2016, methodology): “In the BEC experiments, momentum states of the individual atoms are mapped to the atomic excitations [16, 11].”
Tunable-range, photon-mediated atomic interactions in multimode cavity QED (2017, methodology): “The momentum distribution of the atoms may be detected in time-of-flight imaging, where Bragg peaks appear at wave vectors associated with the λ-period checkerboard lattice [28].”
Breakdown of Photon Blockade: A Dissipative Quantum Phase Transition in Zero Dimensions (2013, background): “Notable experiments are the realization of the Dicke quantum phase transition [43–45] through photon scattering from a superfluid gas in an optical cavity [46] and the observation of Bose-Einstein condensation of photons in an optical microcavity [47].”
Quantum Electrodynamic Control of Matter: Cavity-Enhanced Ferroelectric Phase Transition (2020, background): “Analogs of the Dicke transition have also been explored in ultracold atoms, where matter excitations correspond to different momentum states of atoms [63,64] or hyperfine states in spin-orbitcoupled Bose gases [65].”
Quantum trajectories and open many-body quantum systems (2014, background): “Recent observation of the Dicke phase transition [146, 147] and related optomechanical effects, including the detection of quantised motion and non-classical output light [148, 150] has opened new possibilities for studying many-body dissipative dynamics.”
Open quantum systems with local and collective incoherent processes: Efficient numerical simulations using permutational invariance (2018, background): “[99,100], focuses on how collective couplings can induce quantum phase transitions.”