Although one-dimensional classical spin chains do not exhibit phase transitions, we found that a phase transition does occur when they are coupled to a cavity photon mode. This provides the simplest exactly solvable examples demonstrating that finite-temperature superradiant phase transitions can emerge from long-range fully connected interactions mediated by photons and interactions within the material.

arXiv:2507.01486Physical Review ResearchApr 11, 20261 citation

High temperature superradiant phase transition in novel quantum structures with complex network interface

A. Yu. Bazhenov, Nikitina, M., A. P. Alodjants

arXiv:2507.16316Jul 22, 20250 citations

Optical Materials

Temperature-modulated superradiance near phase transition material

Yuying Liu, Tongbiao Wang, Jianrong Yang, Tianbao Yu, Qinghua Liao

Published Feb 14, 2023• 1 citation

Publisher

DOI: 10.1016/j.optmat.2023.113568

Related papers

Temperature quantum sensor on superradiant phase-transition

A. Yu. Bazhenov, Dmitriy V. Tsarev, A. P. Alodjants

Physica B Condensed MatterNov 19, 201912 citations

Dicke materials as a resource for quantum squeezing

Vaibhav Sharma, Shung-An Koh, Jonathan Stepp +8 more

We study magnetic materials whose low energy physics can be effectively described by a Dicke model, which we term Dicke materials. We show how a Dicke model emerges in such materials due to a coexistence of fast-dispersing and slow-dispersing spins, which are strongly coupled. Analogous to the paradigmatic Dicke model describing light-matter interactions, these materials also exhibit signatures of a superradiant phase transition. The ground state near the superradiant phase transition is expected to be squeezed, making Dicke materials a resource for quantum metrology and witnessing entanglement in solid-state systems. However, as an entanglement measure, squeezing can be sensitive to perturbations that are otherwise irrelevant for usual correlation functions and order parameters. Motivated by the prospect of observing squeezing in such Dicke materials, we study the robustness of ground state squeezing under ubiquitous imperfections such as finite temperature, disorder, and local interactions. Using analytical and numerical techniques, we show that the squeezing obtained is perturbatively stable against these imperfections and quantitatively evaluate regimes promising for experimental observation.We study magnetic materials whose low energy physics can be effectively described by a Dicke model, which we term Dicke materials. We show how a Dicke model emerges in such materials due to a coexistence of fast-dispersing and slow-dispersing spins, which are strongly coupled. Analogous to the paradigmatic Dicke model describing light-matter interactions, these materials also exhibit signatures of a superradiant phase transition. The ground state near the superradiant phase transition is expected to be squeezed, making Dicke materials a resource for quantum metrology and witnessing entanglement in solid-state systems. However, as an entanglement measure, squeezing can be sensitive to perturbations that are otherwise irrelevant for usual correlation functions and order parameters. Motivated by the prospect of observing squeezing in such Dicke materials, we study the robustness of ground state squeezing under ubiquitous imperfections such as finite temperature, disorder, and local interactions. Using analytical and numerical techniques, we show that the squeezing obtained is perturbatively stable against these imperfections and quantitatively evaluate regimes promising for experimental observation.

quant-pharXiv:2603.22416Mar 25, 20260 citations

Phase transition to superradiance in a multicomponent system

VIORICA N. GHEORGHE

Applied Physics BNov 1, 19850 citations

Superradiant phase transitions

Sivasubramanian Somu

Jan 1, 20040 citations

Exactly solvable phase transition in a cavity-coupled one-dimensional Ising chain

Shuntaro Otake, Motoaki Bamba

arXiv:2507.01486Physical Review ResearchApr 11, 20261 citation

High temperature superradiant phase transition in novel quantum structures with complex network interface

A. Yu. Bazhenov, Nikitina, M., A. P. Alodjants

In the present work we propose a novel quantum material concept, which enables super- and/or ultrastrong interaction of two-level systems with the photonic field in a complex network. Within the mean field approximation we examine phase transition to superradiance that results in two excitation (polariton) branches and is accompanied by the appearance of non-zero macroscopic polarization of two-level systems. We characterize the statistical properties of networks by the first, ${\langle}k{\rangle}$ , and second normalized, $ζ\equiv{\langle}k^2{\rangle}/{\langle}k{\rangle}$ , moments for node degree distribution. We have shown that the Rabi frequency is essentially enhanced due to the topology of the network within the anomalous domain where ${\langle}k{\rangle}$ and $ζ$ sufficiently grow. The multichannel (multimode) structure of matter-field interaction leads superstrong coupling that provides primary behavior of the high temperature phase transition. The results obtained pave the way to design new photonic and polaritonic circuits, quantum networks for efficient processing quantum information at high (room) temperatures.In the present work we propose a novel quantum material concept, which enables super- and/or ultrastrong interaction of two-level systems with the photonic field in a complex network. Within the mean field approximation we examine phase transition to superradiance that results in two excitation (polariton) branches and is accompanied by the appearance of non-zero macroscopic polarization of two-level systems. We characterize the statistical properties of networks by the first, ${\langle}k{\rangle}$, and second normalized, $ζ\equiv{\langle}k^2{\rangle}/{\langle}k{\rangle}$, moments for node degree distribution. We have shown that the Rabi frequency is essentially enhanced due to the topology of the network within the anomalous domain where ${\langle}k{\rangle}$ and $ζ$ sufficiently grow. The multichannel (multimode) structure of matter-field interaction leads superstrong coupling that provides primary behavior of the high temperature phase transition. The results obtained pave the way to design new photonic and polaritonic circuits, quantum networks for efficient processing quantum information at high (room) temperatures.

arXiv:2507.16316Jul 22, 20250 citations

{\langle}k{\rangle}

, and second normalized,

ζ\equiv{\langle}k^2{\rangle}/{\langle}k{\rangle}

, moments for node degree distribution. We have shown that the Rabi frequency is essentially enhanced due to the topology of the network within the anomalous domain where

{\langle}k{\rangle}

and

ζ

sufficiently grow. The multichannel (multimode) structure of matter-field interaction leads superstrong coupling that provides primary behavior of the high temperature phase transition. The results obtained pave the way to design new photonic and polaritonic circuits, quantum networks for efficient processing quantum information at high (room) temperatures.