Temperature difference induced entanglement of a two-level atom and a thermal field

Eugene K. Bashkirov

Ling Zhou, H. S. Song, C Li

We study the entanglement between two two-level atoms simultaneously interacting with a single-mode thermal field through a two-photon process. When the two atoms are initially in different states they can be entangled through interaction with the thermal field, and the entanglement induced by nonlinear interaction is larger than that induced by linear interaction. On the basis of our results we review two entanglement criteria.

Fuli Li, Han Xiong, Muhammad Suhail Zubairy

We show how atomic coherence can lead to entanglement between two thermal fields at a temperature $T$. We first show that the passage of a three-level atom in $V$ configuration without coherence cannot create entanglement. However, if the excited states are driven by a microwave field, the resulting atomic coherence can lead to entanglement between the thermal fields. We show that, no matter how high the temperature of the fields is, the thermal fields can always be entangled in the presence of atomic coherence.

胡要花, 方卯发

Mohsen Abbasi

Shi‐Biao Zheng

We show that a cavity field can evolve from an initial displaced mixed thermal state to a macroscopic superpositions of displaced thermal states via resonant interaction with a two-level atom. As a macroscopic system (meter) is really in a mixed state before coupling with the microscopic system at some temperature, our result is important for studying the quantum measurement problem and decoherence under real conditions. For the two-mode case, entanglement of displaced thermal states between the modes can be obtained.