Inhibiting decoherence of two-level atom in thermal bath by presence of boundaries

TL;DR

This paper investigates how boundaries can be used to inhibit decoherence of a two-level atom in a thermal electromagnetic field, showing that specific boundary conditions and atom polarizations can preserve quantum coherence.

Contribution

It demonstrates that boundaries, especially parallel reflecting ones, can effectively prevent decoherence of a transversely polarizable atom in a thermal bath, a novel approach to quantum coherence preservation.

Findings

Quantum coherence decreases without boundaries due to thermal effects.

Boundaries can inhibit decoherence for transversely polarizable atoms.

Specific distances between boundaries can prevent decoherence entirely.

Abstract

We study, in the paradigm of open quantum systems, the dynamics of quantum coherence of a static polarizable two-level atom which is coupled with a thermal bath of fluctuating electromagnetic field in the absence and presence of boundaries. The purpose is to find the conditions under which the decoherence can be inhibited effectively. We find that without boundaries, quantum coherence of the two-level atom inevitably decreases due to the effect of thermal bath. However, the quantum decoherence, in the presence of a boundary, could be effectively inhibited when the atom is transversely polarizable and near this boundary. In particular, we find that in the case of two parallel reflecting boundaries, the atom with a parallel dipole polarization at arbitrary location between these two boundaries will be never subjected to decoherence provided we take some special distances for the two boundaries.