## Dynamical behaviour of the field entropy versus the scaled time τ = λ<em>t</em> in the presence of nonlinearity functions: (a) <em>g</em>(<em>n</em>) = 1, (b) g(n)=L_{n}^{1}(eta ^{2})[(n+1)L_{n}^{0}(eta ^{2})]^{-1}, η = 0.2, (c) g(n)=1/sqrt{n}, and (d) g(n)=sqrt{n+ u }, ν = 3, when the atom and field are assumed to be initially in an excited state and in a coherent state with |α|<sup>2</sup> = 10, respectively

2013-06-27T00:00:00Z (GMT) by
<p><strong>Figure 2.</strong> Dynamical behaviour of the field entropy versus the scaled time τ = λ<em>t</em> in the presence of nonlinearity functions: (a) <em>g</em>(<em>n</em>) = 1, (b) g(n)=L_{n}^{1}(\eta ^{2})[(n+1)L_{n}^{0}(\eta ^{2})]^{-1}, η = 0.2, (c) g(n)=1/\sqrt{n}, and (d) g(n)=\sqrt{n+\nu }, ν = 3, when the atom and field are assumed to be initially in an excited state and in a coherent state with |α|<sup>2</sup> = 10, respectively. The left plots correspond to the influence of intensity-dependent coupling for fixed <em>p</em> (<em>p</em> = 2) and the right plots show the effect of the atomic motion and field-mode structure by considering <em>p</em> = 2 (continuous line), <em>p</em> = 4 (dot-dashed line) and <em>p</em> = 6 (dashed line).</p> <p><strong>Abstract</strong></p> <p>In this paper, we study the interaction between a moving Λ-type three-level atom and a single-mode cavity field in the presence of intensity-dependent atom–field coupling. After obtaining the state vector of the entire system explicitly, we study the nonclassical features of the system such as quantum entanglement, position–momentum entropic squeezing, quadrature squeezing and sub-Poissonian statistics. According to the obtained numerical results we illustrate that the squeezed period, the duration of entropy squeezing and the maximal squeezing can be controlled by choosing the appropriate nonlinearity function together with entering the atomic motion effect by the suitable selection of the field-mode structure parameter. Also, the atomic motion, as well as the nonlinearity function, leads to the oscillatory behaviour of the degree of entanglement between the atom and field.</p>