Publication details

Optimal Probabilistic Storage and Retrieval of Unitary Channels


SEDLÁK Michal BISIO Alessandro ZIMAN Mário

Year of publication 2019
Type Article in Periodical
Magazine / Source Physical Review Letters
MU Faculty or unit

Faculty of Informatics

Keywords quantum learning; quantum networks
Description We address the question of quantum memory storage for quantum dynamics. In particular, we design an optimal protocol for N -> 1 probabilistic storage and retrieval of unitary channels on d-dimensional quantum systems. If we access the unknown unitary gate only N times, the optimal success probability of perfect single-use retrieval is N /(N -1 + d(2)). The derived size of the memory system exponentially improves the known upper bound on the size of the program register needed for probabilistic programmable quantum processors. Our results are closely related to probabilistic perfect alignment of reference frames and probabilistic port-based teleportation.
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