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Generalized Limits for Single-Parameter Quantum Estimation

Sergio Boixo·Steven T. Flammia·Carlton M. Caves·JM Geremia
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Abstract

We develop generalized bounds for quantum single-parameter estimation problems for which the coupling to the parameter is described by intrinsic multi-system interactions. For a Hamiltonian with $k$-system parameter-sensitive terms, the quantum limit scales as $1/N^k$ where $N$ is the number of systems. These quantum limits remain valid when the Hamiltonian is augmented by any parameter independent interaction among the systems and when adaptive measurements via parameter-independent coupling to ancillas are allowed.

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Sergio Boixo, Steven T. Flammia, Carlton M. Caves, JM Geremia. 2006-11-21. Generalized Limits for Single-Parameter Quantum Estimation. https://doi.org/10.1103/physrevlett.98.090401

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