Probing the quantum vacuum with an artificial atom in front of a mirror

TL;DR

This paper demonstrates how a mirror can shape quantum vacuum fluctuations, allowing control over an artificial atom's interaction with the vacuum and effectively hiding it from quantum fluctuations.

Contribution

It introduces a method to engineer and suppress vacuum fluctuations using a mirror, enabling control over atom-vacuum interactions in quantum systems.

Findings

Vacuum fluctuations can be suppressed by a factor of 50 using a mirror.

The weakest observed fluctuation strength is 0.02 quanta.

The technique allows hiding an atom from the quantum vacuum.

Abstract

Quantum fluctuations of the vacuum are both a surprising and fundamental phenomenon of nature. Understood as virtual photons flitting in and out of existence, they still have a very real impact, \emph{e.g.}, in the Casimir effects and the lifetimes of atoms. Engineering vacuum fluctuations is therefore becoming increasingly important to emerging technologies. Here, we shape vacuum fluctuations using a "mirror", creating regions in space where they are suppressed. As we then effectively move an artificial atom in and out of these regions, measuring the atomic lifetime tells us the strength of the fluctuations. The weakest fluctuation strength we observe is 0.02 quanta, a factor of 50 below what would be expected without the mirror, demonstrating that we can hide the atom from the vacuum.