Speaker
Description
We investigate how environmental noise and atomic state purity jointly shape entanglement dynamics in a two-atom cavity QED system described by the single-mode Tavis–Cummings model. The atoms are initially prepared either in maximally entangled Bell states or in mixed Werner states, while the cavity field is modeled by generalized single-mode squeezed coherent thermal states, allowing thermal and quantum noise to compete on equal footing. Atom–atom and atom–field entanglement are characterized using concurrence and negativity, respectively.
We show that thermal photons strongly degrade entanglement and prolong entanglement sudden death, whereas squeezing counteracts decoherence and enhances entanglement resilience. A central result is the striking qualitative difference between pure and mixed atomic states: Bell states not only sustain stronger entanglement but also actively induce nonclassical field states, while Werner states suppress both entanglement and field nonclassicality, even in the presence of squeezing.
We further demonstrate that interaction mechanisms such as dipole–dipole coupling, detuning, and Kerr nonlinearity provide powerful tools for controlling entanglement flow. In particular, Kerr nonlinearity enables tunable redistribution of entanglement between atomic and atom–field subsystems, with the direction and efficiency of transfer governed by the initial atomic mixedness.
Our results highlight atomic state purity as a key control parameter for protecting and steering entanglement in noisy light–matter systems, with implications for realistic cavity-based quantum technologies.
| Keyword-1 | Tavis-Cummings model |
|---|---|
| Keyword-2 | Werner state |