• Corpus ID: 204838240

An approximate description of quantum states

@article{Paini2019AnAD,
  title={An approximate description of quantum states},
  author={Marco Paini and Amir Kalev},
  journal={arXiv: Quantum Physics},
  year={2019}
}
We introduce an approximate description of an $N$-qubit state, which contains sufficient information to estimate the expectation value of any observable with precision independent of $N$. We show, in fact, that the error in the estimation of the observables' expectation values decreases as the inverse of the square root of the number of the system's identical preparations and increases, at most, linearly in a suitably defined, $N$-independent, seminorm of the observables. Building the… 

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