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arXiv · 1310.6043

Heisenberg-limited atom clocks based on entangled qubits

Eric M. Kessler·Peter Kómár·Michael Bishof·Liang Jiang·Anders S. Sørensen·Jun Ye·Mikhail D. Lukin
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Abstract

We present a quantum-enhanced atomic clock protocol based on groups of sequentially larger Greenberger-Horne-Zeilinger (GHZ) states, that achieves the best clock stability allowed by quantum theory up to a logarithmic correction. The simultaneous interrogation of the laser phase with such a cascade of GHZ states realizes an incoherent version of the phase estimation algorithm that enables Heisenberg-limited operation while extending the Ramsey interrogation time beyond the laser noise limit. We compare the new protocol with state of the art interrogation schemes, and show that entanglement allow a significant quantum gain in the stability for short averaging time.

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Eric M. Kessler, Peter Kómár, Michael Bishof, Liang Jiang, Anders S. Sørensen, Jun Ye, Mikhail D. Lukin. 2013-10-22. Heisenberg-limited atom clocks based on entangled qubits. https://doi.org/10.1103/physrevlett.112.190403

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