Tripartite Entanglement Among Atoms in Cavity Quantum Electrodynamics when Atom Off-resonantly Interacting with Cavity Field

Abstract

The tripartite Negativity is adopted to quantify the degree of entanglement among three subsystems. The situation is considered that three identical two-level atoms are trapped in a single-mode optical cavity, and each atom off-resonantly interacts with cavity field via a one-photon hopping. When there is a dipole-dipole interaction between atoms, the tripartite entanglement dynamics among atoms is studied. The influences of detuning between atom and cavity field and the strength of dipole-dipole interaction of two atoms on the tripartite entanglement are discussed. The calculation results indicate that the tripartite entanglement among atoms is strengthened with increasing of the detuning, and it is also strengthened with increasing of the strength of dipole-dipole interaction of two atoms. Under the case of large detuning, the tripartite entanglement among atoms exhibits quasi-periodic oscillations, and its oscillation frequency is accelerated with increasing of the strength of dipole-dipole interaction between two atoms.