Criticality-enhanced Electric Field Gradient Sensor with Single Trapped Ions

TL;DR

This paper introduces a quantum sensor using a single trapped ion near a dissipative critical point, achieving enhanced electric field gradient sensitivity through criticality and continuous monitoring, surpassing standard quantum limits.

Contribution

It presents a novel driven-dissipative quantum sensor leveraging criticality in a trapped ion system with an efficient continuous readout mechanism for improved sensitivity.

Findings

Achieves criticality-enhanced sensing precision beyond the standard quantum limit.

Demonstrates robustness of the sensor to experimental imperfections.

Utilizes phonon counting with high efficiency despite low photon collection.

Abstract

We propose and analyze a driven-dissipative quantum sensor that is continuously monitored close to a dissipative critical point. The sensor relies on the critical open Rabi model with the spin and phonon degrees of freedom of a single trapped ion to achieve criticality-enhanced sensitivity. Effective continuous monitoring of the sensor is realized via a co-trapped ancilla ion that switches between dark and bright internal states conditioned on a `jump' of the phonon population which, remarkably, achieves nearly perfect phonon counting despite a low photon collection efficiency. By exploiting both dissipative criticality and efficient continuous readout, the sensor device achieves highly precise sensing of oscillating electric field gradients at a criticality-enhanced precision scaling beyond the standard quantum limit, which we demonstrate is robust to the experimental imperfections in real-world applications.