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arXiv:0807.4762 · Physical Review A

Backaction noise produced via cavity-aided nondemolition measurement of an atomic clock state

Igor Teper, Geert Vrijsen, Jongmin Lee, Mark A. Kasevich

Published Nov 18, 2008• 27 citations
arXivHTMLPDF

Abstract

We use a quantum nondemolition measurement to probe the collective pseudospin of an atomic ensemble in a high-finesse optical cavity. We analyze the backaction antisqueezing produced by the measurement process to show that our protocol could create conditional spin squeezing in the atomic ensemble.
DOI
10.1103/physreva.78.051803

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We use the vacuum Rabi splitting to perform quantum nondemolition measurements that prepare a conditionally spin squeezed state of a collective atomic psuedospin. We infer a 3.4(6) dB improvement in quantum phase estimation relative to the standard quantum limit for a coherent spin state composed of uncorrelated atoms. The measured collective spin is composed of the two-level clock states of nearly 10(6) (87)Rb atoms confined inside a low finesse F=710 optical cavity. This technique may improve atomic sensor precision and/or bandwidth, and may lead to more precise tests of fundamental physics.
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