An atom with only two energy eigenvalues is described by a two-dimensional state space spanned by the two energy eigenstates is called a two-level atom. We consider the interaction between a two-level atom system with a constant velocity. An analytic solution of the systems which interacts with a quantized field is provided. Furthermore, the significant effect of the temperature on ... Read more

In this paper, we study the dynamics of entanglement between three-level atom and optical field, initially prepared in the squeezed coherent state. We discuss the dynamical behavior of the geometric phase and entanglement, measured by the von Neumann entropy, with and without rotating wave approximation during the time of evolution. The effect of the squeezing and detuning parameters on the ... Read more

We construct a complete representation of the atomic information entropy of an arbitrary multi-level system. Our approach is applicable to all scenarios in which the quantum state shared by a single particle and fields is known. As illustrations we apply our findings to a single four-level atom strongly coupled to a cavity field and driven by a coherent laser field. ... Read more

* _ Abdel-Aty_, M. S. Abdallah and A.-S. F. Obada, “Entropy and entanglement of isotropic coupled oscillators,“Nonlinear Optics Research Progress”,. ed. F. Columbus (Nova Science Publishers, Inc., New York, USA 2007) Read more

We study the uncertainty relations between photon number and canonical phase of a multilevel system. All the relevant quantities can be sampled directly from the measured phase-dependent quadrature distribution. Some comments are made on the extension of these relations to the case where the Hilbert space is of infinite dimension. We describe its theoretical basis and discuss its practical relevance, ... Read more

The first harmonic components of the absorption/dispersion spectrum, the intensity and Boltzmann-Gibbs entropy are investigated within a truncated continued fraction approach for the non-autonomous system of ordinary differential equations modelling a coherently driven 2-level atom bathed in a broadband squeezed vacuum. For the given data, regions of amplification, steep variational dispersion are identified. The Boltzmann-Gibbs entropy shows dense (less dense) ... Read more

We present a general framework for the quasi-mutual entropy to quantify the entanglement degree for a two-level atom interacting with a Holstein-Primakoff SU(1,1) coherent state, taking into account an arbitrary form of the intensity-dependent coupling. We derive an explicit expression for the entanglement degree in terms of the density matrix elements which does not involve the diagonal approximation, and establish ... Read more