Observation of the phononic Lamb shift with a synthetic vacuum

TL;DR

This paper reports the experimental observation of the phononic Lamb shift in a synthetic vacuum created with ultracold atomic gases, enabling high-precision tests of quantum vacuum effects in many-body systems.

Contribution

It introduces a novel synthetic vacuum system that allows direct observation of the phononic Lamb shift, bridging quantum vacuum theory and ultracold atom experiments.

Findings

Observation of the phononic Lamb shift in ultracold gases

Demonstration of switching between empty space and quantum vacuum

Potential for high-precision benchmarking of quantum vacuum theories

Abstract

The quantum vacuum fundamentally alters the properties of embedded particles. In contrast to classical empty space, it allows for creation and annihilation of excitations. For trapped particles this leads to a change in the energy spectrum, known as Lamb shift. Here, we engineer a synthetic vacuum building on the unique properties of ultracold atomic gas mixtures. This system makes it possible to combine high-precision spectroscopy with the ability of switching between empty space and quantum vacuum. We observe the phononic Lamb shift, an intruiguing many-body effect orginally conjectured in the context of solid state physics. Our study therefore opens up new avenues for high-precision benchmarking of non-trivial theoretical predictions in the realm of the quantum vacuum.