Quantum phase properties of a state driven by a classical field

TL;DR

This paper investigates the quantum phase properties of a nonclassical cavity field generated by an atom driven through a cavity, analyzing phase distribution, phase functions, dispersion, and correlation functions.

Contribution

It introduces a detailed analysis of quantum phase characteristics of a driven atom-cavity system, focusing on the statistical properties of the output field.

Findings

Quantum phase distribution and phase functions are characterized.

The phase dispersion and second-order correlation function are evaluated.

The study provides insights into the phase behavior of atom-driven cavity fields.

Abstract

We consider a nonclassical state generated by an atom-cavity field interaction in presence of a driven field. In the scheme, the two-level atom is moved through the cavity and driven by a classical field. The atom interacts dispersively with the cavity field, which results in a photon-number-dependent Stark shift. Assuming that the atom enters the cavity in the excited state $|{a}\rangle$, the obtained output cavity field is taken into account. The state vector $|\psi(t)\rangle$ describes the entire atom-field system but in our work we deal with the statistical aspects of the cavity field only. The quantum state that corresponds to the output cavity field is obtained by tracing out the atom part from $|{\psi(t)}\rangle\langle{\psi(t)}|$. Different quantum phase properties such as quantum phase distribution, angular $Q$ phase function, phase dispersion are evaluated for the obtained radiation field. The second-order correlation function $g^2(0)$, an indirect phase characteristic is also considered.