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arXiv · 1608.06152

Quantum back-action evading measurement of collective mechanical modes

C. F. Ockeloen-Korppi·E. Damskägg·J. -M. Pirkkalainen·A. A. Clerk·M. J. Woolley·M. A. Sillanpää
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Abstract

The standard quantum limit constrains the precision of an oscillator position measurement. It arises from a balance between the imprecision and the quantum back-action of the measurement. However, a measurement of only a single quadrature of the oscillator can evade the back-action and be made with arbitrary precision. Here we demonstrate quantum back-action evading measurements of a collective quadrature of two mechanical oscillators, both coupled to a common microwave cavity. The work allows for quantum state tomography of two mechanical oscillators, and provides a foundation for macroscopic mechanical entanglement and force sensing beyond conventional quantum limits.

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C. F. Ockeloen-Korppi, E. Damskägg, J. -M. Pirkkalainen, A. A. Clerk, M. J. Woolley, M. A. Sillanpää. 2016-09-27. Quantum back-action evading measurement of collective mechanical modes. https://doi.org/10.1103/physrevlett.117.140401

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