Quantum tricriticality, a unique form of high-order criticality, is expected to exhibit fascinating features including unconventional critical exponents and universal scaling laws. However, a quantum tricritical point (QTCP) is much harder to access, and the corresponding phenomena at tricriticality have rarely been investigated. In this study, we explore a tricritical quantum Rabi model, which incorporates a nontrivial parameter for adjusting the coupling ratio between a cavity and a three-level atom. The QTCP emerges at the intersection of a first- and second-order superradiant phase transitions according to Landau theory. By using finite-frequency scaling analyses for quantum fluctuations and the mean photon number, universal critical exponents differentiate the QTCP from the second-order critical point. We find that the phase transition at the tricritical point goes beyond the conventional second-order phase transition. Our work explores an interesting direction in the generalization of the well-known Rabi model for the study of higher-order critical points due to its high control and tunability.Quantum tricriticality, a unique form of high-order criticality, is expected to exhibit fascinating features including unconventional critical exponents and universal scaling laws. However, a quantum tricritical point (QTCP) is much harder to access, and the corresponding phenomena at tricriticality have rarely been investigated. In this study, we explore a tricritical quantum Rabi model, which incorporates a nontrivial parameter for adjusting the coupling ratio between a cavity and a three-level atom. The QTCP emerges at the intersection of a first- and second-order superradiant phase transitions according to Landau theory. By using finite-frequency scaling analyses for quantum fluctuations and the mean photon number, universal critical exponents differentiate the QTCP from the second-order critical point. We find that the phase transition at the tricritical point goes beyond the conventional second-order phase transition. Our work explores an interesting direction in the generalization of the well-known Rabi model for the study of higher-order critical points due to its high control and tunability.

arXiv:2402.12827Feb 20, 20240 citations

Critical Exponents, Scaling, and Renormalization Group

WORLD SCIENTIFIC eBooksNov 1, 20210 citations

Scaling of fluctuations and critical exponents

M. Broidioi, M Van Canneyt

Journal of Statistical PhysicsJan 1, 19961 citation

Quantum tricriticality in a generalized quantum Rabi system

You-Qi Lu, Yuyu Zhang

Abstract Quantum tricriticality, a unique form of high-order criticality, is expected to exhibit fascinating features including unconventional critical exponents and universal scaling laws. However, a quantum tricritical point (QTCP) is much harder to access, and the corresponding phenomena at tricriticality have rarely been investigated. In this study, we explore a tricritical quantum Rabi model, which incorporates a non-trivial parameter to adjust the coupling ratio between a cavity and a three-level atom. The QTCP emerges at the intersection of first- and second-order superradiant phase transitions according to Landau theory. By using finite-frequency scaling analysis on quantum fluctuations and the average photon number, universal critical exponents differentiate the QTCP from the second-order critical point. Our results indicate that the phase transition at the tricritical point goes beyond the conventional second-order phase transition. Our work explores an interesting direction in the generalization of the well-known Rabi model for the study of higher-order critical points due to its high control and tunability.Abstract Quantum tricriticality, a unique form of high-order criticality, is expected to exhibit fascinating features including unconventional critical exponents and universal scaling laws. However, a quantum tricritical point (QTCP) is much harder to access, and the corresponding phenomena at tricriticality have rarely been investigated. In this study, we explore a tricritical quantum Rabi model, which incorporates a non-trivial parameter to adjust the coupling ratio between a cavity and a three-level atom. The QTCP emerges at the intersection of first- and second-order superradiant phase transitions according to Landau theory. By using finite-frequency scaling analysis on quantum fluctuations and the average photon number, universal critical exponents differentiate the QTCP from the second-order critical point. Our results indicate that the phase transition at the tricritical point goes beyond the conventional second-order phase transition. Our work explores an interesting direction in the generalization of the well-known Rabi model for the study of higher-order critical points due to its high control and tunability.

New Journal of PhysicsMay 24, 20245 citations

Universality in the critical exponents δ and η

J. Ricardo de Sousa

Physics Letters AFeb 1, 19993 citations

"Proposal for a notation at tricritical points": A comment

David J. Bergman, Ora Entin-wohlman A

We re-examine the scaling relations found by Griffiths for the so-called subsidiary tricritical exponents. We find that some of these relations depend on whether the line $M={M}_{t}$ lies in the tricritical, the critical, or the intermediate region in the space of thermodynamic variables, as well as on the regular parts of some thermodynamic functions. We also extend these laws to the case where scaling holds only in a curvilinear coordinate system based on the critical line.We re-examine the scaling relations found by Griffiths for the so-called subsidiary tricritical exponents. We find that some of these relations depend on whether the line $M={M}_{t}$ lies in the tricritical, the critical, or the intermediate region in the space of thermodynamic variables, as well as on the regular parts of some thermodynamic functions. We also extend these laws to the case where scaling holds only in a curvilinear coordinate system based on the critical line.

Physical review. B, Solid stateJul 1, 19743 citations

We re-examine the scaling relations found by Griffiths for the so-called subsidiary tricritical exponents. We find that some of these relations depend on whether the line

M={M}_{t}

lies in the tricritical, the critical, or the intermediate region in the space of thermodynamic variables, as well as on the regular parts of some thermodynamic functions. We also extend these laws to the case where scaling holds only in a curvilinear coordinate system based on the critical line.