Linear Ascending Metrological Algorithm

TL;DR

The paper introduces LAMA, a quantum metrological algorithm that significantly improves measurement precision in decohering quantum systems, especially for magnetic field sensing with superconducting transmon devices.

Contribution

LAMA is a novel quantum algorithm designed to enhance measurement precision under decoherence, surpassing existing methods in quantum metrology.

Findings

LAMA effectively mitigates dephasing and relaxation effects.

Demonstrates improved magnetic field measurement precision.

Applicable to superconducting transmon qudit sensors.

Abstract

The ubiquitous presence of shot noise sets a fundamental limit to the measurement precision in classical metrology. Recent advances in quantum devices and novel quantum algorithms utilizing interference effects are opening new routes for overcoming the detrimental noise tyranny. However, further progress is limited by the restricted capability of existing algorithms to account for the decoherence pervading experimental implementations. Here, adopting a systematic approach to the evaluation of effectiveness of metrological procedures, we devise the Linear Ascending Metrological Algorithm (LAMA), which offers a remarkable increase in precision in the demanding situation where a decohering quantum system is used to measure a continuously distributed variable. We introduce our protocol in the context of magnetic field measurements, assuming superconducting transmon devices as sensors operated in a qudit mode. Our findings demonstrate a quantum-metrological procedure capable of mitigating detrimental dephasing and relaxation effects.