Squeezed-light-induced quantum phase transition in the Jaynes-Cummings model

Quantum phase transition and quench dynamics in the Jaynes-Cummings model with squeezed light are investigated. We find a special unitary transformation that removes the nonintegrable squeezing interaction when the qubit frequency far outweighs the field frequency. The eigenenergies and the eigenstates of the normal and superradiant phases are derived analytically. We demonstrate that the system exhibits a second-order quantum phase transition at a phase-boundary-induced nonlinearly by squeezed light. This phase boundary requires neither an ultrastrong coupling regime nor multiqubits, which lessens the difficulty of the experiment. The entanglement entropy is very close to its maximum value as the squeezing strength increases in the superradiant phase. In quench dynamics, the nonlinear relation between the residual energy and the squeezing strength is obtained analytically.

Automated summary

Quantum phase transition and quench dynamics in the Jaynes-Cummings model with squeezed light were investigated, where a special unitary transformation was found to remove nonintegrable squeezing interaction. Eigenenergies and eigenstates of normal and superradiant phases were derived analytically, demonstrating a second-order quantum phase transition induced nonlinearly at the phase boundary by squeezed light. Entanglement entropy approached its maximum value as squeezing strength increased in the superradiant phase, and a nonlinear relationship between residual energy and squeezing strength was analytically obtained in quench dynamics.