2018/01/31 by Ryosuke Imai, Y. Yamanaka, Yoshiya Yamanaka
Computer Science · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Degenerate energy levels #Eigenvalues and eigenvectors #Excited state #Hamiltonian (control theory) #Photon #Physics #Quantum Information and Cryptography #Quantum electrodynamics #Quantum mechanics #Spectroscopy and Quantum Chemical Studies #Spontaneous symmetry breaking #Superradiance #Symmetry breaking #Thermodynamic limit #cond-mat.quant-gas #quant-ph
paper · pdf · doi:10.1016/j.physleta.2018.09.002
published as Phys. Lett. A 382, 3333 (2018) · 12 pages
arxiv created 2018/09/06 · openalex publication_date 2018/10/09 · arxiv updated 2018/10/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the finite-size Dicke model with photon leakage. It is shown that the symmetry breaking states, which are characterized by non-vanishing ⟨ a ⟩ ≠ 0 and correspond to the ground states in the superradiant phase in the thermodynamic limit, are stable, while the eigenstates of the isolated finite-size Dicke Hamiltonian conserve parity symmetry. We introduce and analyze an effective master equation that describes the dynamics of a pair of the symmetry breaking states that are the degenerate lowest energy eigenstates in the superradiant region with photon leakage. It becomes clear that photon leakage is essential to stabilize the symmetry breaking states and to realize the superradiant phase without the thermodynamic limit. Our theoretical analysis provides an alternative interpretation using the finite-size model to explain results from cold atomic experiments showing superradiance with the symmetry breaking in an optical cavity.