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arXiv · 1201.3940

The elusive Heisenberg limit in quantum enhanced metrology

Rafal Demkowicz-Dobrzanski·Jan Kolodynski·Madalin Guta
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Abstract

We provide efficient and intuitive tools for deriving bounds on achievable precision in quantum enhanced metrology based on the geometry of quantum channels and semi-definite programming. We show that when decoherence is taken into account, the maximal possible quantum enhancement amounts generically to a constant factor rather than quadratic improvement. We apply these tools to derive bounds for models of decoherence relevant for metrological applications including: dephasing,depolarization, spontaneous emission and photon loss.

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Rafal Demkowicz-Dobrzanski, Jan Kolodynski, Madalin Guta. 2012-01-18. The elusive Heisenberg limit in quantum enhanced metrology. https://doi.org/10.1038/ncomms2067

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