Physical Review A
Even and odd coherent states for multimode parametric systems
V. V. Dodonov, Vladimir I. Man’ko, Dmitri E. Nikonov
Abstract
The multimode even and odd coherent states (multimode Schr\"odinger cat states) are constructed for polymode parametric oscillators of the electromagnetic field. The evolution of the photon distribution function is evaluated explicitly. The distribution function is expressed in terms of multivariable Hermite polynomials; the means and dispersions of the function are calculated. The conditions for the existence of squeezing are formulated. The correlations between the different modes of the Schr\"odinger cat states are studied. The transformation of the initial Schr\"odinger cat states under the action of a resonant external force is investigated.