Phase-Controlled Atom-Photon Entanglement in a Three-Level V-Type Atomic System via Spontaneously Generated Coherence

Abstract

Abstract:We investigate the dynamical behavior of the atom-photon entanglement in a V-type three-level quantum system using the atomic reduced entropy. It is shown that an atom and photons are entangled at the steady-state; however disentanglement can also be achieved in an special condition. It is demonstrated that in the presence of quantum interference induced by spontaneous emission, the reduced entropy and the atom-photon entanglement are phase-dependent. A non-stationary solution is also obtained when the quantum interference due to the spontaneous emission is completely included.

The influence of spontaneously generated coherence on atom-photon entanglement in a Λ-type system with an incoherent pump

“…While considering the SGC effect, we apply the EIT effect to the research on the entorpy of entanglement. Due to the presence of the incoherent pump, even though the probe is very weak, we are surprised to find that the SGC effect can influence the DEM [39][40][41][42][43][44] conditionally. Moreover, by comparing with the gain or absorption of the atom system in both steady Figure 1.…”

“…Generally, narrowing down the decay rate is expected. However, a previous work demonstrated that the SGC effect between two spontaneous emissions in the V-type system has a major role in establishing the atom-photon entanglement [39]. It is found that in the presence of SGC effect, the reduced entropy and the atom-photon entanglement are phase-dependent.…”

“…Generally, features of the systems are not controlled by the phase of the applied fields without the SGC effect. However, previous work have shown that the SGC effect can modify the response of the atom-photon entanglement [39,47] and therefore we have to regard Rabi frequencies as complex parameters. Supposing that the phases of the probe and the coupling fields are φ and φ , we can rewrite the density-matrix equations using two are real parameters.…”

“…It has been shown that a declining partial entropy stands for the case that each component tends to a pure state and becomes disentangled. To the contrary, a growing one stands for that they tend to lose their individuality and become entangled [39,45].…”

“…In Mohammad Abazari and collegues' article, which dealt with a three-level V-type system [39], each of the matrix elements is inclusive of the additional term resulted from the SGC effect, therefore the spontaneously emission coherence have a far greater impact on the entropy and the degree of the entanglement. However, for the Λ-type system, only a few expressions are inclusive of the SGC effect.…”