Eur. Phys. J. D 47, 295-302 (2008)
https://doi.org/10.1140/epjd/e2008-00046-x

Effects of a classical homogeneous gravitational field on the cavity-field entropy and generation of the Schrödinger-cat states in the Jaynes-Cummings model

¹ Department of Physics, Islamic Azad University - Shahreza Branch, Shahreza, Isfahan, Iran
² Quantum Optics Group, Department of Physics, University of Isfahan, Isfahan, Iran

Corresponding authors: ^a majid471702@yahoo.com - ^b mhnaderi2001@yahoo.com - ^c soltan@sci.ui.ac.ir

Received: 19 November 2007
Published online: 14 March 2008

Abstract

In this paper, we examine the effects of the gravitational field on the dynamical evolution of the cavity-field entropy and the creation of the Schrödinger-cat state in the Jaynes-Cummings model. We consider a moving two-level atom interacting with a single mode quantized cavity-field in the presence of a classical homogeneous gravitational field. Based on an su(2) algebra, as the dynamical symmetry group of the model, we derive the reduced density operator of the cavity-field which includes the effects of the atomic motion and the gravitational field. Also, we obtain the exact solution and the approximate solution for the system-state vector, and examine the atomic dynamics. By considering the temporal evolution of the cavity-field entropy as well as the dynamics of the Q-function of the cavity-field we study the effects of the gravitational field on the generation of the Schrödinger-cat states of the cavity-field by using the Q-function, field entropy and approximate solution for the system-state vector. The results show that the gravitational field destroys the generation of the Schrödinger-cat state of the cavity-field.