Thermal nonlinear coherent states on a flat space and on a sphere

Abstract

In this paper, we first define thermal nonlinear coherent states on a sphere and show that these states are essentially two-mode squeezed nonlinear coherent states of the sphere at zero temperature. Then we consider quantum statistical properties of the thermal sphere nonlinear coherent states. In particular, we investigate temperature effects on transition of the constructed states from nonclassical states to classical ones. By using the Mandel parameter, we obtain a transition temperature and show that this transition temperature increases by increasing the curvature of the physical space. It turns out that, increasing curvature of the space provides nonlinear coherent states with nonclassical properties in higher temperature ranges. © 2013 AIP Publishing LLC.