Toward Spin Squeezing with Trapped Ions

TL;DR

This paper discusses the principles and recent progress in achieving spin squeezing with trapped ions, aiming to surpass the standard quantum limit and approach the Heisenberg limit for precision measurements.

Contribution

It introduces a method for spin squeezing using geometric phase gates with beryllium ions in a Penning trap, advancing quantum metrology techniques.

Findings

Demonstrated spin squeezing with trapped ions

Achieved measurement precision beyond the standard quantum limit

Progress toward Heisenberg limit in ion-based sensors

Abstract

Building robust instruments capable of making interferometric measurements with precision beyond the standard quantum limit remains an important goal in many metrology laboratories. We describe here the basic concepts underlying spin squeezing experiments that allow one to surpass this limit. In priniciple it is possible to reach the so-called Heisenberg limit, which constitutes an improvement in precision by a factor $\sqrt{N}$, where $N$ is the number of particles on which the measurement is carried out. In particular, we focus on recent progress toward implementing spin squeezing with a cloud of beryllium ions in a Penning ion trap, via the geometric phase gate used more commonly for performing two-qubit entangling operations in quantum computing experiments.