Spontaneous symmetry breaking in frustrated triangular atom arrays due to cooperative light scattering
arXiv:2206.15216 · doi:10.1103/PhysRevResearch.4.043039
Abstract
We demonstrate the presence of an optical phase transition with frustration-induced spontaneous symmetry breaking in a triangular planar atomic array due to cooperative light-mediated interactions. We show how the array geometry of triangle unit cells at low light intensities leads to degenerate collective radiative excitations forming nearly flat bands. We drive degenerate pairs of collective excitations to be equally populated in both cases of the atomic polarization in the lattice plane and perpendicular to it. At higher intensities, above specific threshold values, this symmetry in the populations is spontaneously broken. We also develop an effective few-mode model that provides semianalytic descriptions of the symmetry-breaking threshold and infinite-lattice limit phase transition. Surprisingly, we find how excitations due to dipolar interactions correspond to optical analogs of those found in frustrated magnets and superfluids, with closely related symmetry-breaking mechanisms despite the significant physical differences between these systems, opening potential for simulating even quantum magnetism. Transmitted light through the array conveys information about symmetry breaking in the hysteresis behavior of the spectrum. Moreover, in a Mott-insulator state, the atomic positions are subject to zero-point quantum fluctuations. Interpreting each stochastic realization as a light-induced quantum measurement of the atomic position configuration, we find how strong nonlinearities and even weak position uncertainties lead to considerable measurement-induced symmetry breaking, while ensemble-averaging over many realizations restores the original symmetry and the unbroken state. Larger position uncertainty results in the formation of domains of different broken symmetries.
15 pages, 9 figures
References in corpus (19)
- Many-Body Physics with Ultracold Gases
- Cooperative resonances in light scattering from two-dimensional atomic arrays
- Tunable-range, photon-mediated atomic interactions in multimode cavity QED
- Emergent superfluid crystals, frustration, and topologically defected states in multimode cavity QED
- Storing light with subradiant correlations in arrays of atoms
- Subradiant Bell states in distant atomic arrays
- Long-range interacting many-body systems with alkaline-earth-metal atoms
- Self-organization of atoms in a cavity field: threshold, bistability and scaling laws
- Photonic Band Structure of Two-dimensional Atomic Lattices
- Photon blockade with ground-state neutral atoms
- A superatom picture of collective nonclassical light emission and dipole blockade in atom arrays
- Transmission of near-resonant light through a dense slab of cold atoms
- Theoretical formalism for collective electromagnetic response of discrete metamaterial systems
- Phase-imprinted multiphoton subradiant states
- Classical stochastic measurement trajectories: Bosonic atomic gases in an optical cavity and quantum measurement backaction
- Light propagation in systems involving two-dimensional atomic lattices
- Bistable optical transmission through arrays of atoms in free space
- Parity-time symmetry and coherent perfect absorption in a cooperative atom response
- Nonuniform phases in the geometrically frustrated dissipative XYZ model