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arXiv · 1610.07689

Pumped-up SU(1,1) interferometry

Stuart S. Szigeti·Robert J. Lewis-Swan·Simon A. Haine
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Abstract

Although SU(1,1) interferometry achieves Heisenberg-limited sensitivities, it suffers from one major drawback: only those particles outcoupled from the pump mode contribute to the phase measurement. Since the number of particles outcoupled to these `side modes' is typically small, this limits the interferometer's absolute sensitivity. We propose an alternative `pumped-up' approach where all the input particles participate in the phase measurement, and show how this can be implemented in spinor Bose-Einstein condensates and hybrid atom-light systems - both of which have experimentally realized SU(1,1) interferometry. We demonstrate that pumped-up schemes are capable of surpassing the shot-noise limit with respect to the total number of input particles and are never worse than conventional SU(1,1) interferometry. Finally, we show that pumped-up schemes continue to excel - both absolutely and in comparison to conventional SU(1,1) interferometry - in the presence of particle losses, poor particle-resolution detection, and noise on the relative phase difference between the two side modes. Pumped-up SU(1,1) interferometry therefore pushes the advantages of conventional SU(1,1) interferometry into the regime of high absolute sensitivity, which is a necessary condition for useful quantum-enhanced devices.

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Stuart S. Szigeti, Robert J. Lewis-Swan, Simon A. Haine. 2017-04-11. Pumped-up SU(1,1) interferometry. https://doi.org/10.1103/physrevlett.118.150401

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