Ideal state discrimination with an O(1)-qubit quantum computer
Quantum Physics
2012-02-01 v1
Abstract
We show how to optimally discriminate between K distinct quantum states, of which N copies are available, using one-at-a-time interactions with each of the N copies. While this task (famously) requires joint measurements on all N copies, we show that it can be solved with one-at-a-time "coherent measurements" performed by an apparatus with log(K) qubits of quantum memory. We apply the same technique to optimal discrimination between K distinct N-particle matrix product states of bond dimension D, using a coherent measurement apparatus with log(K) + log(D) qubits of memory.
Cite
@article{arxiv.1201.6625,
title = {Ideal state discrimination with an O(1)-qubit quantum computer},
author = {Robin Blume-Kohout and Sarah Croke and Michael Zwolak},
journal= {arXiv preprint arXiv:1201.6625},
year = {2012}
}
Comments
5 pages, 1 figure, O(1) qubits