Spontaneous emission entanglement

If a quantum state starting from Rb63p3/2), then we take C4 = 1 and C3 = 0. The process described by the arrival state C4 = 0 and C3 = 1 can be seen in a two-fold manner (1) The > -photon is sent away into the cavity by spontaneous emission (2) The linear superposition becomes periodic in time where the state is an entangled state the energy hco is no longer available. 

An example of entangled states in a two-atom system are the symmetric and antisymmetric states, which correspond to the symmetric and antisymmetric combinations of the atomic dipole moments, respectively [1,7,21]. These states are created by the dipole-dipole interaction between the atoms and are characterized by different spontaneous decay rates that the symmetric state decays with an enhanced, whereas the antisymmetric state decays with a reduced spontaneous emission rate [7]. For the case of two atoms confined into the region much smaller than the optical wavelength, the antisymmetric state does not decay at all, and therefore can be regarded as a decoherence-free state. 

It can be easily deduced from the above that entanglement between two modes [F((d)<2] and squeezing in the respective modes are based on the eombined effeet of the correlated spontaneous emission (((8v) ) =1) and the sum mode intensity noise reduetion [5 ((o)<0]. Two faetors are responsible for entanglement and squeezing. The first is the eorrelated spontaneous emission. Only the sum mode B is coupled to the medium while the relative mode B is deeoupled fiem the system. The second is the dynamical noise reduction. For yi <<72 the population in state - ) is negligible. Then the four-level system in Fig. 11 is reduced to a three-level system ( 0 ), and 13 )). In the reduced system, the succession of < 3) the two-step incoherent process and the... 

H. Xiong, M. O. Scully, M. S. Zubairy. Correlated Spontaneous Emission Laser as an Entanglement Amplifier. Physical Review Letters 2004 Jul 21 94(2) 023601(4). 

Shahid Qamar, Han Xiong, M. Suhail Zubairy. Influence of pump-phase fluctuations on entanglement generation using a correlated spontaneous-emission laser. Physical Revew A 2007 0ct3 75(6) 062305(10). 

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