PERIODIC ENTANGLEMENT BETWEEN THE INTERNAL AND EXTERANL DEGREE OF FREEDOM OF A TRAPPED ION IN A STANDING WAVE LASER
驻波激光场中囚禁离子内外自由度的周期纠缠

We have investigated the quantum entropy and entanglement of the internal and external degrees of freedom of a trapped ion in a standing wave laser by transforming the Hamiltonian to that in the Jaynes-Cummings system for the bare basis of the trapped ion under the Lamb-Dicke limit. Under the off-resonant condition, we have found the periodic entanglement between the internal and external degrees of freedom of a trapped ion.