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arXiv · 1901.02497

Quantum enhanced estimation of diffusion

Dominic Branford·Christos N. Gagatsos·Jai Grover·Alexander J. Hickey·Animesh Datta
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Abstract

Momentum diffusion is a possible mechanism for driving macroscopic quantum systems towards classical behaviour. Experimental tests of this hypothesis rely on a precise estimation of the strength of this diffusion. We show that quantum-mechanical squeezing offers significant improvements, including when measuring position. For instance, with 10dB of mechanical squeezing, experiments would require a tenth of proposed free-fall times. Momentum measurement is better by an additional factor of three, while another quadrature is close to optimal. These have particular implications for the space-based MAQRO proposal -- where it could rule out the spontaneous collapse theory due to Ghirardi, Rimini, and Weber -- as well as terrestrial optomechanical sensing.

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Dominic Branford, Christos N. Gagatsos, Jai Grover, Alexander J. Hickey, Animesh Datta. 2019-09-02. Quantum enhanced estimation of diffusion. https://doi.org/10.1103/physreva.100.022129

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