We propose two parameters which are mutually related to the fidelity between two states1-4 and mean number of photons. We discuss them for situations corresponding to the regular and chaotic behavior of the classical counterpart of Kerr-like quantum system, showing that proposed parameters could be applied as indicators of quantum chaos.
We present a two-dimensional cellular automata (CA) model involving a set of two-level subsystems (”atoms”)
which are located in square lattice, and can emit and absorb quanta of energy. Our model is an extension
of the one-dimensional model discussed in the papers.1, 2 We concentrate on the spreading of disorder in the
system and propose entropic parameters describing two-dimensional system’s dynamics. We show that whereas
entropic measure undergoes saturation effects, its counterpart normalized per number of excitations can exhibit
A model of a nonlinear, damped kicked oscillator is discussed. For such a model intra-mode correlations described by mutual information parameter I[α] based on the Wehrl entropy are considered. Furthermore, the system’s quantum evolution is compared to its classical counterpart. The mutual information parameter is discussed as a proposal for quantum chaos’ witness.
We discuss a chain of three nonlinear oscillators excited by an external field. We show that during system’s evolution squeezed states can be generated in all three modes. Such generated squeezing appears simultaneously in all modes but for different quadratures. We show that degree of the squeezing and time of its appearance depend on the values of the parameters determining strengths of external and internal couplings and dumping of the system.
We discuss the simulation method allowing modeling of quantum unitary dynamics for quantum nonlinear scissors systems. In particular, we consider the model of two nonlinear oscillators (Ker-like coupler) excited by an external field. We show that the time-evolution of the system is closed within a finite set of n-photo states and the Bell-like states are generated. Thus, we prove that the numerical method applied can be used as tools of quantum-mechanical simulations leading to the interesting results.
In this paper we consider a generalized double dispersion equation of Porubov’s type4,5. which describes the propagation of the longitudinal strain waves in the rod. By analogy with the optical case2, the higher orders of nonlinearity have been included which leads to an interesting class of traveling solitary waves for both cases: without cubic nonlinearity and with its presence. The F-expansion method described in3 has been used. As a byproduct, we obtain the results given previously by other authors4,5. It will be shown that our analytical solutions describe very well the results obtained by numerical simulations6.
We investigate two atoms coupled with a quantized field mode. Whereas one is the Jaynes-Cummings (JC)
two-level atom, the other is an autoionizing system with two discrete levels and a continuum of states. In case
interactions between the atoms do not occur, the periodic behavior of the JC atom contrasts with the autoionizing
system. We ask whether or not a seesaw-like interaction between the atoms can change the behavior of the JC
atom. We present photoelectron spectra dependent on the time for various initial states of the field mode.
We propose to adapt the cellular automata approach as a tool for investigation of quantum optical systems. As an example we propose a model comprising a cavity filled with a one dimensional chain of identical two level atoms. To simulate the probabilistic character of a single atom evolution we use the Monte Carlo algorithm. We assume that the cavity is confined by mirrors of the reflectivity r. This fact allows simulation of the cavity losses. In this communication we shall show the influence of the probabilities of photon absorption by a single atom inside the cavity, on the system dynamics.
Schemes for preparation of optical qubits represented by any chosen Superposition of number states, in particular the vacuum and single-photon states. arc studied. The schemes enable truncation of an input light to qubit states via linear or nonlinear processes thus are referred to as the linear or nonlinear quantum scissors. The basic
propertics of the schemes are discussed.
The classical information entropy defined by Wehrl in terms of the Husimi Q-function is discussed and generalized over the concepts of the Wehrl phase distribution, and the Wehrl intermode-correlation parameters. The classical entropic functions are applied to describe the quantum properties of single and/or two-mode optical fields.
We analyze generation of maximally entangled states (EPR and W states) of the conduction-band electron spins in systems of an arbitrary number of semiconductor quantum dots under equivalent-neighbor interactions mediated by a single-mode cavity field. We show that the perfect EPR states in bipartite systems and perfect W
states in multipartite ones can only be generatcd in systems of up to six and four dots, respectively, with single or equivalently, all dots except one excited.