Asymptotical photon distributions in the dissipative Dynamical Casimir Effect

Asymptotical formulas for the photon distribution function of a quantum oscillator with time-dependent frequency and damping coefficients, interacting with a thermal reservoir, are derived in the case of a large mean number of quanta. Different regimes of excitation of an initial thermal state with an arbitrary temperature are considered. New formulas are used to predict the statistical properties of the electromagnetic field created in the experiments on the Dynamical Casimir Effect which are now under preparation.Comment: 11 pages, accepted contribution to CEWQO 2009 proceedings (to appear in Physica Scripta

Creating quanta with "annihilation" operator

An asymmetric nature of the boson `destruction' operator $\hat{a}$ and its `creation' partner $\hat{a}^{\dagger}$ is made apparent by applying them to a quantum state $|\psi>$ different from the Fock state $|n>$. We show that it is possible to {\em increase} (by many times or by any quantity) the mean number of quanta in the new `photon-subtracted' state $\hat{a}|\psi >$. Moreover, for certain `hyper-Poissonian' states $|\psi>$ the mean number of quanta in the (normalized) state $\hat{a}|\psi>$ can be much greater than in the `photon-added' state $\hat{a}^{\dagger}|\psi >$. The explanation of this `paradox' is given and some examples elucidating the meaning of Mandel's $q$-parameter and the exponential phase operators are considered.Comment: 10 pages, LaTex, an extended version with several references added and the text divided into sections; to appear in J. Phys.