Reduction of Classical Measurement Noise via Quantum-Dense Metrology

TL;DR

This paper demonstrates a quantum-dense metrology technique that improves measurement sensitivity beyond the shot noise limit by utilizing additional phase space information, even in the presence of classical noise.

Contribution

The authors present a proof-of-principle experiment showing that QDM can enhance sensitivity without discarding data, overcoming classical noise pollution.

Findings

Achieved sub-shot-noise measurement performance

Utilized additional phase space information to improve sensitivity

Maintained data integrity despite classical noise contamination

Abstract

Quantum-dense metrology (QDM) constitutes a special case of quantum metrology in which two orthogonal phase space projections of a signal are simultaneously sensed beyond the shot noise limit. Previously it was shown that the additional sensing channel that is provided by QDM contains information that can be used to identify and to discard corrupted segments from the measurement data. Here, we demonstrate a proof-of-principle experiment in which this information is used for improving the sensitivity without discarding any measurement segments. Our measurement reached sub-shot-noise performance although initially strong classical noise polluted the data.