Non-destructive detection of ions using atom-cavity collective strong coupling

TL;DR

This paper introduces a non-destructive optical cavity technique to detect trapped ions by observing changes in vacuum-Rabi splitting caused by collective strong coupling with ultracold atoms.

Contribution

It demonstrates a novel method using atom-cavity coupling to detect ions non-destructively and measure ion-atom collision rates with high fidelity.

Findings

Vacuum-Rabi splitting varies with trapped Rb+ ions presence

Method enables fast, non-destructive detection of ions

Allows measurement of atomic-state selective collision rates

Abstract

We present a technique, based on atoms coupled to an optical cavity, for non-destructive detection of trapped ions. We demonstrate the vacuum-Rabi splitting (VRS), arising due to the collective strong coupling of ultracold Rb atoms to a cavity, to change in presence of trapped Rb+ ions. The Rb+ ions are optically dark and the Rb atoms are prepared in a dark magneto-optical trap (MOT). The VRS is measured on an optically open transition of the initially dark Rb atoms. The measurement itself is fast, non-destructive and has sufficient fidelity to permit the measurement of atomic-state selective ion-atom collision rate. This demonstration illustrates a method based on atom-cavity coupling to measure two particle interactions generically and non-destructively.