The dynamics of squeezing across a quantum phase transition in two basic models, viz., the one-axis twisting model in a transverse field and the Dicke model, is investigated using Holstein-Primakoff representation in the large spin limit. Near the phase boundary between the disordered (normal) and the ordered (superradiant) phases, the strength of spin and photon squeezing and the duration of time for which the system stays in the highly squeezed state are found to exhibit strong power-law growth with distance from the quantum critical point. The critical exponent for squeezing time is found to be 1/2 in both of the models, and for squeezing strength, it is shown to be 1/2 in the one-axis twisting model and 1 for the Dicke model, which in the limit of extreme detuning also becomes 1/2.The dynamics of squeezing across a quantum phase transition in two basic models, viz., the one-axis twisting model in a transverse field and the Dicke model, is investigated using Holstein-Primakoff representation in the large spin limit. Near the phase boundary between the disordered (normal) and the ordered (superradiant) phases, the strength of spin and photon squeezing and the duration of time for which the system stays in the highly squeezed state are found to exhibit strong power-law growth with distance from the quantum critical point. The critical exponent for squeezing time is found to be 1/2 in both of the models, and for squeezing strength, it is shown to be 1/2 in the one-axis twisting model and 1 for the Dicke model, which in the limit of extreme detuning also becomes 1/2.

arXiv:2006.04056Physical Review ASep 2, 20203 citations

The weakly coupled infinite Dicke model

Reinhard Honegger

Physica A Statistical Mechanics and its ApplicationsApr 1, 19966 citations

Atom-only descriptions of the driven-dissipative Dicke model

François Damanet, Andrew J. Daley, Jonathan Keeling

We investigate how to describe the dissipative spin dynamics of the driven-dissipative Dicke model, describing $N$ two-level atoms coupled to a cavity mode, after adiabatic elimination of the cavity mode. To this end, we derive a Redfield master equation which goes beyond the standard secular approximation and large detuning limits. We show that the secular (or rotating wave) approximation and the large detuning approximation both lead to inadequate master equations, that fail to predict the Dicke transition or the damping rates of the atomic dynamics. In contrast, the full Redfield theory correctly predicts the phase transition and the effective atomic damping rates. Our work provides a reliable framework to study the full quantum dynamics of atoms in a multimode cavity, where a quantum description of the full model becomes intractable.We investigate how to describe the dissipative spin dynamics of the driven-dissipative Dicke model, describing $N$ two-level atoms coupled to a cavity mode, after adiabatic elimination of the cavity mode. To this end, we derive a Redfield master equation which goes beyond the standard secular approximation and large detuning limits. We show that the secular (or rotating wave) approximation and the large detuning approximation both lead to inadequate master equations, that fail to predict the Dicke transition or the damping rates of the atomic dynamics. In contrast, the full Redfield theory correctly predicts the phase transition and the effective atomic damping rates. Our work provides a reliable framework to study the full quantum dynamics of atoms in a multimode cavity, where a quantum description of the full model becomes intractable.

arXiv:1901.02473Physical Review AMar 25, 201970 citations

Long-time evolution in the dicke model

S. M. Chumakov, M. Kozierowski, A. A. Mamedov

Journal of Russian Laser ResearchJan 1, 19910 citations

Non-equilibrium dynamics of the Dicke model for mesoscopic aggregates: signatures of superradiance

Sebastian Fuchs, Joachim Ankerhold, M. P. Blencowe +1 more

Abstract The dynamics of the Dicke model, which describes the interaction of N two-level atoms with a resonant field mode, is studied in the presence of dissipation and in strong non-equilibrium for a moderate number of atoms. Starting from a highly excited state, it is investigated to what extent signatures of superradient phenomena known from the thermodynamic limit , namely, superradiant light emission and atom-field correlations characteristic for the superradiant phase, appear on transient time scales. Attention is also paid to subtleties of modeling dissipation in the weak coupling limit and to the dynamics in phase space. The latter allows phase space correlators to be defined as indicators for collective behavior on transient time scales. These findings may be of relevance for the realization of Dicke physics with superconducting circuits.Abstract The dynamics of the Dicke model, which describes the interaction of N two-level atoms with a resonant field mode, is studied in the presence of dissipation and in strong non-equilibrium for a moderate number of atoms. Starting from a highly excited state, it is investigated to what extent signatures of superradient phenomena known from the thermodynamic limit , namely, superradiant light emission and atom-field correlations characteristic for the superradiant phase, appear on transient time scales. Attention is also paid to subtleties of modeling dissipation in the weak coupling limit and to the dynamics in phase space. The latter allows phase space correlators to be defined as indicators for collective behavior on transient time scales. These findings may be of relevance for the realization of Dicke physics with superconducting circuits.

arXiv:1501.07841Journal of Physics B Atomic Molecular and Optical PhysicsJan 8, 20169 citations

We investigate how to describe the dissipative spin dynamics of the driven-dissipative Dicke model, describing

N

two-level atoms coupled to a cavity mode, after adiabatic elimination of the cavity mode. To this end, we derive a Redfield master equation which goes beyond the standard secular approximation and large detuning limits. We show that the secular (or rotating wave) approximation and the large detuning approximation both lead to inadequate master equations, that fail to predict the Dicke transition or the damping rates of the atomic dynamics. In contrast, the full Redfield theory correctly predicts the phase transition and the effective atomic damping rates. Our work provides a reliable framework to study the full quantum dynamics of atoms in a multimode cavity, where a quantum description of the full model becomes intractable.