Spatial decoherence factor via the qubit-field interaction

TL;DR

This paper investigates how the interaction between a two-level atom and a cavity field causes spatial decoherence, revealing the influence of field statistics and phase properties on the decoherence process and atomic translation.

Contribution

It introduces a decoherence factor D that encodes spatial coherence loss due to qubit-field interaction, highlighting the role of field statistics and phase in the process.

Findings

Field statistics influence the decoherence factor D.

Field phase properties contribute to the imaginary part of D.

The relation between atomic momentum and the imaginary part of the density matrix is analyzed.

Abstract

We analyze the time evolution of an initial spatial coherence for a two level atom whose internal degrees of freedom interact with a single mode of a cavity field. When the qubit-field subsystem is taken as an environment, the translational dynamics experiences a decoherence process which may be encoded in a decoherence factor D. We find that the field statistics affects D through the alternative paths the system-environment may follow along their entanglement, while eventual field phase properties give rise to an imaginary part of D which is related to the atomic translation. From the decoherence perspective, we analyze the relation between the atomic momentum and the imaginary part of the atomic spatial density matrix, and some considerations on its asymptotic behavior are brought into question at the conclusion of the paper.