Entanglement Signature of the Superradiant Quantum Phase Transition

Fuente: arXiv
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Main Authors: Vesperini, Arthur, Cini, Matteo, Franzosi, Roberto
Format: Preprint
Published: 2024
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author Vesperini, Arthur
Cini, Matteo
Franzosi, Roberto
author_facet Vesperini, Arthur
Cini, Matteo
Franzosi, Roberto
contents Entanglement and quantum correlations between atoms are not usually considered key ingredients of the superradiant phase transition. Here we consider the Tavis-Cummings model, a solvable system of two-levels atoms, coupled with a single-mode quantized electromagnetic field. This system undergoes a superradiant phase transition, even in a finite-size framework, accompanied by a spontaneous symmetry breaking, and an infinite sequence of energy level crossings. We find approximated expressions for the ground state, its energy, and the position of the level crossings, valid in the limit of a very large number of photons with respect to that of the atoms. In that same limit, we find that the number of photons scales quadratically with the coupling strength, and linearly with the system size, providing a new insight into the superradiance phenomenon. Resorting to novel multipartite measures, we then demonstrate that this quantum phase transition is accompanied by a crossover in the quantum correlations and entanglement between the atoms (qubits). The latters therefore represent suited order parameters for this transition. Finally, we show that these properties of the quantum phase transition persist in the thermodynamic limit.
format Preprint
id arxiv_https___arxiv_org_abs_2404_19373
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Entanglement Signature of the Superradiant Quantum Phase Transition
Vesperini, Arthur
Cini, Matteo
Franzosi, Roberto
Quantum Physics
Mathematical Physics
Optics
Entanglement and quantum correlations between atoms are not usually considered key ingredients of the superradiant phase transition. Here we consider the Tavis-Cummings model, a solvable system of two-levels atoms, coupled with a single-mode quantized electromagnetic field. This system undergoes a superradiant phase transition, even in a finite-size framework, accompanied by a spontaneous symmetry breaking, and an infinite sequence of energy level crossings. We find approximated expressions for the ground state, its energy, and the position of the level crossings, valid in the limit of a very large number of photons with respect to that of the atoms. In that same limit, we find that the number of photons scales quadratically with the coupling strength, and linearly with the system size, providing a new insight into the superradiance phenomenon. Resorting to novel multipartite measures, we then demonstrate that this quantum phase transition is accompanied by a crossover in the quantum correlations and entanglement between the atoms (qubits). The latters therefore represent suited order parameters for this transition. Finally, we show that these properties of the quantum phase transition persist in the thermodynamic limit.
title Entanglement Signature of the Superradiant Quantum Phase Transition
topic Quantum Physics
Mathematical Physics
Optics
url https://arxiv.org/abs/2404.19373