Breakdown of the rotating-wave approximation in entanglement description of spin anti-correlated states

Details Breakdown of the rotating-wave approximation in entanglement description of spin anti-correlated states Breakdown of the rotating-wave approximation in entanglement description of spin anti-correlated states

2008-11-28

arxiv.org/abs/0811.4633v2

Phys. Rev. A 79, 044305 (2009)

Physics

Quantum Physics

Scientific paper

It is well established that an entanglement encoded in the Bell states of a two-qubit system with correlated spins exhibits completely different evolution properties than that encoded in states with the anti-correlated spins. A complete and abrupt loss of the entanglement, called the entanglement sudden death, can be found to occur for the spin correlated states, but the entanglement evolves without any discontinuity or decays asymptotically for the spin anti-correlated states. We consider the evolution of an initial entanglement encoded in the spin anti-correlated states and demonstrate that the asymptotic behavior predicted before occurs only in the weak coupling limit or equivalently when the rotating-wave approximation (RWA) is made on the interaction Hamiltonian of the qubits with the field. If we do not restrict ourselves to the RWA, we find that the entanglement undergoes a discontinuity, the sudden death phenomenon. We illustrate this behavior by employing an efficient scheme for entanglement evolution between two cold-trapped atoms located inside a single-mode cavity. Although only a single excitation is initially present in the system, we find that the two-photon excited state, which plays the key role for the discontinuity in the behavior of the entanglement, gains a population over a short time of the evolution. When the RWA is made on the interaction, the two-photon excited state remains unpopulated for all times and the discontinuity is absent. We attribute this phenomenon to the principle of complementarity between the evolution time and energy, and the presence of the counter-rotating terms in the interaction Hamiltonian.

Affiliated with

Also associated with

No associations

Rating

Breakdown of the rotating-wave approximation in entanglement description of spin anti-correlated states does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Breakdown of the rotating-wave approximation in entanglement description of spin anti-correlated states, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Breakdown of the rotating-wave approximation in entanglement description of spin anti-correlated states will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-709991