English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

It is well established that an entanglement encoded in the Bell states of atwo-qubit system with correlated spins exhibits completely different evolutionproperties than that encoded in states with the anti-correlated spins. Acomplete and abrupt loss of the entanglement, called the entanglement suddendeath, can be found to occur for the spin correlated states, but theentanglement evolves without any discontinuity or decays asymptotically for thespin anti-correlated states. We consider the evolution of an initialentanglement encoded in the spin anti-correlated states and demonstrate thatthe asymptotic behavior predicted before occurs only in the weak coupling limitor equivalently when the rotating-wave approximation (RWA) is made on theinteraction Hamiltonian of the qubits with the field. If we do not restrictourselves to the RWA, we find that the entanglement undergoes a discontinuity,the sudden death phenomenon. We illustrate this behavior by employing anefficient scheme for entanglement evolution between two cold-trapped atomslocated inside a single-mode cavity. Although only a single excitation isinitially present in the system, we find that the two-photon excited state,which plays the key role for the discontinuity in the behavior of theentanglement, gains a population over a short time of the evolution. When theRWA is made on the interaction, the two-photon excited state remainsunpopulated for all times and the discontinuity is absent. We attribute thisphenomenon to the principle of complementarity between the evolution time andenergy, and the presence of the counter-rotating terms in the interactionHamiltonian.

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