Magnetic field sensing beyond the standard quantum limit under the effect of decoherence

By Y. Matsuzaki, Simon C. Benjamin, Joseph Francis Fitzsimons. 2011

163 citations recorded by the source corpus.

Entangled states can potentially be used to outperform the standard quantum limit by which every classical sensor is bounded. However, entangled states are very susceptible to decoherence, and so it is not clear whether one can really create a superior sensor to classical technology via a quantum strategy which is subject to the effect of realistic noise. This paper presents an investigation of how a quantum sensor composed of many spins is affected by independent dephasing. We adopt general noise models including non-Markovian effects, and in these noise models the performance of the sensor depends crucially on the exposure time of the sensor to the field. We have found that, by choosing an appropriate exposure time within the non-Markovian time region, an entangled sensor does actually beat the standard quantum limit. Since independent dephasing is one of the most typical sources of noise in many systems, our results suggest a practical and scalable approach to beating the standard quantum limit.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/34c7309239de0788bdfeda03e8dfd157accaf39c

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In Artificial Intelligence

In Atomic and Molecular Physics, and Optics

Citations in the corpus

Quantum limits in optical interferometry (2014, background): “…times, in which the SQL-like scaling bounds may in principle be circumvented by: adjusting decoherence geometry (Arrad et al., 2014; Chaves et al., 2013; Dür et al., 2014; Kessler et al., 2013) or by considering Non-Markovian short-time behaviour (Chin et al., 2012; Matsuzaki et al., 2011).”
Quantum metrology with nonclassical states of atomic ensembles (2016, background): “It has been shown that this condition can be achieved for relatively short interrogation times in the case of non-Markovian noise (Chin et al., 2012; Matsuzaki et al., 2011) and also when considering dephasing noise perpendicular to phase encoding evolution (Chaves et al., 2013).”
Quantum-enhanced measurements without entanglement (2017, background): “Recent research has focussed on finding optimal states in the presence of decoherence, and at least for non-Markovian noise, a certain improvement can still be obtained from entangled states (Chin et al., 2012; Matsuzaki et al., 2011).”