Entanglement in a driven two-qubit system coupled to a common cavity

Amit Dey

A system, comprised of a qubit pair coupled to a common cavity, is studied with the aim of establishing qubit entanglement. This study is the sequel of the paper Phys. Rev. A 111, 043705 (2025), where similar model was investigated for an initially vacuum cavity. In the present manuscript the cavity with finite initial occupancy is considered and the effect of asymmetric qubit cavity couplings is investigated. For a closed system scenario, the ratio of the qubit-cavity couplings shows a threshold beyond which no maximally-entangled qubit state is available. The threshold value is shown to depend on the excitation level of the cavity. For a driven-dissipative case steady state entanglement is shown to depend non-monotonically on the qubit drive. Intricate interplay of drive, dissipation, and coupling asymmetry is shown to be pivotal for steady-state entanglement generation.

Mohammad Mehdi Sahrapour, Nancy Makri

Amit Dey

Generation of quantum entanglement between a pair of qubits is studied in a cavity-QED platform. The qubit pair is placed inside a common cavity environment. We show that the relative strength of qubit-photon couplings is crucial for establishing interqubit entanglement. Resonance as well as off resonance between the qubits and photon are considered. For the off-resonant case we detect a threshold value of the coupling ratio, beyond which the maximally entangled state is always available. The resonant case displays interesting nonmonotonic behavior, where the maximum entanglement peaks at an intermediate coupling ratio. The driven-dissipative dynamics of our model exhibits nontrivial dependence of steady-state entanglement on the drive strength.

Saeed Pegahan

Saeed Pegahan, Morteza Soltani, Fardin Kheirandish

Amit Dey

Generation of quantum entanglement between a pair of qubits is studied in a cavity-QED platform. The qubit pair is placed inside a common cavity environment. We show that the relative strength of qubit-photon couplings is crucial for establishing inter-qubit entanglement. Resonance as well as off-resonance between the qubits and photon are considered . For off-resonant case we detect a threshold value of coupling ratio, beyond which maximally entangled state is always available. The resonant case displays interesting non-monotonic behavior, where the maximum entanglement peaks at an intermediate coupling ratio. The driven-dissipative dynamics of our model exhibits non-trivial dependence of steady-state entanglement on the drive strength.