# Quantum logic spectroscopy with ions in thermal motion

## TL;DR

This paper demonstrates a quantum logic spectroscopy method using a mixed-species geometric phase gate on trapped ions, enabling precise transition identification, reduced temperature sensitivity, and quantum-enhanced frequency measurement, with applications in atomic clocks and quantum error correction.

## Contribution

The paper experimentally implements a novel quantum logic spectroscopy technique that combines probe and information transfer in a single pulse, improving sensitivity and applicability.

## Key findings

- Successful realization of the mixed-species geometric phase gate
- Reduced temperature sensitivity in spectroscopy measurements
- Observation of quantum-enhanced frequency sensitivity in multi-ion chains

## Abstract

A mixed-species geometric phase gate has been proposed for implementing quantum logic spectroscopy on trapped ions that combines probe and information transfer from the spectroscopy to the logic ion in a single pulse. We experimentally realize this method, show how it can be applied as a technique for identifying transitions in currently intractable atoms or molecules, demonstrate its reduced temperature sensitivity, and observe quantum-enhanced frequency sensitivity when it is applied to multi-ion chains. Potential applications include improved readout of trapped-ion clocks and simplified error syndrome measurements for quantum error correction.