Recovering Quantum Gates from Few Average Gate Fidelities - Kölner UniversitätsPublikationsServer

Roth, I, Kueng, R., Kimmel, S., Liu, Y-K, Gross, D., Eisert, J. and Kliesch, M. (2018). Recovering Quantum Gates from Few Average Gate Fidelities. Phys. Rev. Lett., 121 (17). COLLEGE PK: AMER PHYSICAL SOC. ISSN 1079-7114

Full text not available from this repository.

DOI:10.1103/PhysRevLett.121.170502

Abstract

Characterizing quantum processes is a key task in the development of quantum technologies, especially at the noisy intermediate scale of today's devices. One method for characterizing processes is randomized benchmarking, which is robust against state preparation and measurement errors and can be used to benchmark Clifford gates. Compressed sensing techniques achieve full tomography of quantum channels essentially at optimal resource efficiency. In this Letter, we show that the favorable features of both approaches can be combined. For characterizing multiqubit unitary gates, we provide a rigorously guaranteed and practical reconstruction method that works with an essentially optimal number of average gate fidelities measured with respect to random Clifford unitaries. Moreover, for general unital quantum channels, we provide an explicit expansion into a unitary 2-design, allowing for a practical and guaranteed reconstruction also in that case. As a side result, we obtain a new statistical interpretation of the unitarity-a figure of merit characterizing the coherence of a process.

Item Type:

Journal Article

Creators:

Creators	Email	ORCID	ORCID Put Code
Roth, I	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED
Kueng, R.	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED
Kimmel, S.	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED
Liu, Y-K	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED
Gross, D.	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED
Eisert, J.	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED
Kliesch, M.	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED