Dephasing in an atom

TL;DR

This paper explores quantum dephasing effects in an atom near a dielectric surface, revealing a phenomenon involving a mean electric field formation due to electron state interference violation, distinct from classical ferroelectricity.

Contribution

It introduces a quantum dephasing mechanism causing mean electric field formation near dielectric surfaces, differing from classical polarization effects.

Findings

Dephasing leads to a larger ground state energy compared to a bare atom.

Formation of a mean electric field is due to quantum interference violation.

The phenomenon is fundamentally different from ferroelectricity.

Abstract

When an atom in vacuum is near a surface of a dielectric the energy of a fluctuating electromagnetic field depends on a distance between them resulting, as known, in the force called van der Waals one. Besides this fluctuation phenomenon there is one associated with formation of a mean electric field which is equivalent to an order parameter. In this case atomic electrons are localized within atomic distances close to the atom and the total ground state energy is larger, compared to the bare atom, due to a polarization of the dielectric and a creation of a mean electric field locally distributed in the dielectric. The phenomenon strongly differs from the usual ferroelectricity and has a pure quantum origin connected with a violation of the interference due to dephasing of fluctuating electron states in the atom.