Impact of quantum–classical correspondence on entanglement enhancement by single-mode squeezing

• Continuous-variable entanglement is explored in the Pullen–Edmonds Hamiltonian.
• The local phase-space structure and the entanglement enhancement are related.
• Entanglement enhancement via squeezing is smaller for the chaotic orbit.
• Entanglement enhancement via squeezing is higher for the regular orbit.
• The magnitude of the entanglement enhancement serves as a quantum-chaos indicator.

Quantum entanglement between two field modes can be achieved through the collective squeezing of the two respective modes. If single-mode squeezing is performed prior to such a two-mode squeezing, an enhancement of entanglement production can happen. Interestingly, the occurrence of this enhancement can be implicitly linked to the local classical dynamical behavior via the paradigm of quantum–classical correspondence. In particular, the entanglement generated through quantum chaos is found to be hardly enhanced by prior squeezing, since it is bounded by the saturation value of the maximally entangled Schmidt state with fixed energy. These results illustrate that entanglement enhancement via initial squeezing can serve as a useful indicator of quantum chaotic behaviour.