Probabilistic storage and retrieval of qubit phase gates

Warning

This publication doesn't include Faculty of Sports Studies. It includes Faculty of Informatics. Official publication website can be found on muni.cz.
Authors

SEDLÁK Michal ZIMAN Mário

Year of publication 2020
Type Article in Periodical
Magazine / Source Physical Review A
MU Faculty or unit

Faculty of Informatics

Citation
Web https://doi.org/10.1103/PhysRevA.102.032618
Doi http://dx.doi.org/10.1103/PhysRevA.102.032618
Keywords quantum technologies; quantum information
Attached files
Description Probabilistic storage and retrieval (PSR) of unitary quantum dynamics is possible with exponentially small failure probability with respect to the number of systems used as a quantum memory [M. Sedlák, A. Bisio, and M. Ziman, Phys. Rev. Lett. 122, 170502 (2019)]. Here we study improvements due to a priori knowledge about the unitary transformation to be stored. In particular, we study N-->1 PSR of qubit phase gates, i.e., qubit rotations around the Z axis with an unknown angle, and show that if we access the gate only N times the optimal probability of perfect retrieving of its single use is N/(N+1). We propose a quantum circuit realization for the optimal protocol and show that a programmable phase gate [G. Vidal, L. Masanes, and J. I. Cirac, Phys. Rev. Lett. 88, 047905 (2002)] can be turned into a (2k-1)-->1 optimal PSR of phase gates and requires only k controlled-not gates, while having exponentially small failure probability in k.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.

More info