Superradiant Phase is a Finite Size Effect in Two-photon Processes

Abstract:Two-photon light-matter interactions exhibit distinctive features such as spectral collapse. The two-photon Dicke model has been reported to exhibit a superradiant phase which could be useful in quantum applications. Here we show that this superradiant phase is not a genuine thermodynamic phase but a finite-size effect. Combining analytical and numerical analyses, we demonstrate that the superradiant region shrinks with increasing system size and disappears in the thermodynamic limit, while spectral collapse remains. Our results clarify the nature of superradiant conditions in two-photon systems and constrain its realization in quantum platforms.

Quantum Physics (quant-ph); Statistical Mechanics (cond-mat.stat-mech)

arXiv:2601.19986 [quant-ph]

(or arXiv:2601.19986v2 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2601.19986 Focus to learn more arXiv-issued DOI via DataCite

Phys. Rev. Lett. 137, 053603 (2026)

https://doi.org/10.1103/syq9-z93n Focus to learn more DOI(s) linking to related resources

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