Journal of Chongqing Institute of Technology

Enhanced Squeezing and Entanglement in Parametric Down-conversion Process with Three-level Atoms

Li-hui Sun

Published Jan 1, 2010• 0 citations

Abstract

A system of three-level atoms which are being injected in some state into a cavity at a rate is considered.The master equation of the cavity modes is obtained.The entanglement properties of two-mode field is discussed according to the entanglement criterion proposed by Duan et al.The results show that under some conditions,the system can work as a NPDC.In addition,in order to obtain the bright and strong entangled field,the system should operate over threshold.

Related papers

Enhanced entanglement and squeezing of two-mode field from a double-ladder four-level atom

Wenwu Deng, Huatang Tan, Gao‐xiang Li

The entanglement and squeezing properties of a two-mode field are investigated in the system of a double-ladder four-level atom embedded in a two-mode cavity. It is found that the system can reduce to the nondegenerate parametric oscillator which is responsible for the entanglement and squeezing of a cavity field under suitable conditions. Moreover, compared to the field from the three-level cascade atomic system, the degree of entanglement in the present system can be improved significantly.

Journal of Physics B Atomic Molecular and Optical PhysicsJul 24, 20085 citations

ENTANGLEMENT FOR THE TWO-MODE FIELD IN THREE-LEVEL ATOMIC SYSTEMS

BO ZHANG, Guo-Qin Ge, Yunxia Ping

We investigate entanglement for the two-mode field in three-level atomic systems. Entanglement of the system is demonstrated according to the Duan's criterion.16 It shows that the entanglement has a close relation with the pump intensity. For large pump intensity, particular choice of its phase, zero detuning and cooperativity parameter, perfect entanglement for the two-mode field can be generated outside the cavity.

Modern Physics Letters BMay 29, 20072 citations

Entanglement Generation of Two-mode Field from Two-level Atomic Medium in Optical Cavity

Li Chi

The generation of entangled light via two-level atomic medium inside a two-mode optical cavity is discussed according to the entanglement criterion proposed by Duan et al.We find that,under some conditions,the two-mode cavity field exhibits stable two-mode entanglement.The degree of the entanglement is dependent on the intensity of the pump field,the detuning,and the collective cooperativity.

湖北科技学院学报Jan 1, 20090 citations

Enhanced Squeezing and Entanglement in Nondegenerate Three-Level Laser Coupled to Squeezed Vacuum Reservoir

Ebisa Mosisa

Squeezing and entanglement of a two-mode cascade laser, produced by a three-level atom which is initially prepared by a coherent superposition of the top and bottom levels then injected into a cavity coupled to a two-mode squeezed vacuum reservoir is discussed. I obtain stochastic differential equations associated with the normal ordering using the pertinent master equation. Making use of the solutions of the resulting differential equations, we determined the mean photon number for the cavity mode and their correlation, EPR variables, smallest eigenvalue of the symplectic matrix, intensity difference fluctuation, and photon number correlation. It is found that the squeezed vacuum reservoir increases the degree of the statistical and nonclassical features of light produced by the system. Furthermore, using the criteria developed by logarithm negativity and Hillery-Zubairy criteria, the quantum entanglement of the cavity mode is quantified. It is found that the degree of the entanglement for the system under consideration increases with the squeezing parameter of the squeezed vacuum reservoir.

Advances in Mathematical PhysicsApr 21, 20217 citations

Continuous-variable entanglement in a nondegenerate three-level laser with a parametric oscillator

Eyob Alebachew

We consider a nondegenerate three-level cascade laser with a subthreshold nondegenerate parametric oscillator coupled to a vacuum reservoir. Applying the pertinent master equation, we analyze the squeezing and entanglement properties of the two-mode light produced by this quantum optical system inside and outside the cavity. We also determine the normalized second-order correlation function for the two-mode light as well as for individual mode. We find that the light generated by this system is in a two-mode squeezed state and the state of the system is strongly entangled at steady state. Moreover, the presence of the parametric oscillator leads to an increase in the degree of squeezing and entanglement. We also find that the intermode correlation decreases as the injected atomic coherence decreases in the system.

Physical Review AAug 13, 200759 citations

Quantum Properties of the Field in the System of Λ-type Three-level Atom Interacting with Two-mode Coherent Light Field

卢道明 LU Dao-ming

Considering two Λ-type three-level atoms initially in the entangled state, one atom is poured into the cavity and interacts with a two-mode cavity. The squeezing and antibunching effects of the field are investigated. The influences of the selective atomic measurement and the intensity of the coherent field, which interacts with atom on squeezing and antibunching effect of the field, are discussed. The results obtained by numerical calculations show that squeezing and antibunching effect of the field can be strengthened through selective atomic measurement for atom outside of the cavity.

ACTA PHOTONICA SINICAJan 1, 20100 citations