Robustness of nonclassical superposition states against decoherence

Abstract

We make a comparative study of quadrature squeezing, photon-number distribution and Wigner function in a decayed quantum system. Specifically, for a field mode prepared initially in cat states interacting with a zero-temperature environment, we show that the rate of reduction of the nonclassical effects in this system is proportional to the occurrence of the decoherence process.

On the evolution of superposition of squeezed displaced number states with the multiphoton Jaynes Cummings model

“…Furthermore, the evolution of the quadrature squeezing for the case k = 3 exhibits revivals and collapses similar to those of the atomic inversion of the standard JCM. Actually, this is a novel result and its consequence is that the revival-collapse phenomenon exhibited for the atomic inversion can be measured by homodyne detection via three-photon microcavity [55]. With respect to W function we have found some novel results, which can be summarized as follows: There is a direct relation between the evolution of the values of the W function at the origin in phase space and the evolution of σ z (T ) when the absorption parameter k is odd number.…”

Minimum decoherence cat-like states in Gaussian noisy channels

“…(8). This means that one can promptly derive the Wigner function W β 0 ,θ of a squeezed cat state by simply replacing α 0 with β 0 in Eq.…”

“…Therefore, cat-like states that are available for experiments are usually mixed states that suffered a partial decoherence, and it is crucial to know whether and to which extent superpositions can survive the environmental noise. The theme of decoherence of cat-like states spurred relevant theoretical works [5,6,7,8], especially aimed to select schemes of quantum control and feedback stabilizing coherent superpositions against decoherence [7]. Recent promising experimental results and perspectives continue to keep a widespread interest in this subject [9,10].…”

Evolution of cat states in a dissipative parametric amplifier: decoherence and entanglement

“…We have examined the behaviour of both the photon-number distribution and the W function for these cases using the same values of the parameters as in [5], however, we have taken α = 1 (where squeezing is noticeable) and found that the behaviour of these quantities reflects equally the properties of squeezed light. For more details reader can consult [42].…”