Characteristic time and maximum mixedness: Single mode Gaussian states in dissipative channels

Using the normally ordered Gaussian form of displaced-squeezed thermal field characteristic of average photon numbern, we introduce the photon-added squeezed thermo state (PASTS) and investigate its statistical properties, such as Mandel's Q-parameter, number distribution (as a Legendre polynomial), the Wigner function. We then study its decoherence in a photon-loss channel in term of the negativity of WF by deriving the analytical expression of WF for PASTS. It is found that the WF with single photon-added is always partial negative for the arbitrary values ofn and the squeezing parameter r.

Section: Introductionmentioning

confidence: 99%

Photon-added squeezed thermal states: Statistical properties and its decoherence in a photon-loss channel

Fan

2010

“…In a recent work [20] we studied some characteristics of the GSS, including photon number distribution, Wigner function and von Neumann entropy. We show the results here for the purpose of comparison with the superposition states (similar behaviour was found also in [16], where they studied the 2-entropy of a single-mode field initially in a number state).…”

Section: Von Neumann Entropymentioning

confidence: 99%

“…In figures (20) and (21) we show the results for the GSS with ν 0 = 3 and even and odd superposition states with β 0 = 0.8 and β 0 = 2.0, respectively. Both the even and the odd superposition states behave similarly in these cases.…”

Section: Gss Versus Superposition States -Fidelitymentioning

confidence: 99%

See 1 more Smart Citation

Quantifying the decay of quantum properties in single-mode states

Souza

Nemes

Santos

et al. 2008

Self Cite

The dissipative dynamics of Gaussian squeezed states (GSS) and coherent superposition states (CSS) are analytically obtained and compared. Time scales for sustaining different quantum properties such as squeezing, negativity of the Wigner function or photon number distribution are calculated. Some of these characteristic times also depend on initial conditions. For example, in the particular case of squeezing, we find that while the squeezing of CSS is only visible for small enough values of the field intensity, in GSS it is independent of this quantity, which may be experimentally advantageous. The asymptotic dynamics however is quite similar as revealed by the time evolution of the fidelity between states of the two classes.Comment: Accepted versio

Mixedness and entanglement for two-mode Gaussian states

Souza

Drumond

Nemes

et al. 2012

Self Cite

We analytically exploit the two-mode Gaussian states nonunitary dynamics. We show that in the zero temperature limit, entanglement sudden death (ESD) will always occur for symmetric states (where initial single mode compression is z0) provided the two mode squeezing r0 satisfies 0 < r0 < 1 2 log(cosh(2z0)). We also give the analytical expressions for the time of ESD. Finally, we show the relation between the single modes initial impurities and the initial entanglement, where we exhibit that the later is suppressed by the former.