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arXiv · 1211.3570

Quantum-Dense Metrology

Sebastian Steinlechner·Jöran Bauchrowitz·Melanie Meinders·Helge Müller-Ebhardt·Karsten Danzmann·Roman Schnabel
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Abstract

Quantum metrology utilizes entanglement for improving the sensitivity of measurements. Up to now the focus has been on the measurement of just one out of two non-commuting observables. Here we demonstrate a laser interferometer that provides information about two non-commuting observables, with uncertainties below that of the meter's quantum ground state. Our experiment is a proof-of-principle of quantum dense metrology, and uses the additional information to distinguish between the actual phase signal and a parasitic signal due to scattered and frequency shifted photons. Our approach can be readily applied to improve squeezed-light enhanced gravitational-wave detectors at non-quantum noise limited detection frequencies in terms of a sub shot-noise veto-channel.

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Sebastian Steinlechner, Jöran Bauchrowitz, Melanie Meinders, Helge Müller-Ebhardt, Karsten Danzmann, Roman Schnabel. 2012-11-15. Quantum-Dense Metrology. https://arxiv.org/abs/1211.3570

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