Berlin 2014 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 64: Quantum information: Concepts and methods V
Q 64.4: Talk
Friday, March 21, 2014, 14:45–15:00, Kinosaal
Minimal Quantum Gate Characerisation and its Applications to Fidelity Estimation — •Daniel Reich1, Giulia Gualdi1,2,3, and Christiane Koch1 — 1Theoretische Physik, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel — 2Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, 50019 Sesto Fiorentino, Italy — 3QSTAR, Largo Enrico Fermi 2, 50125 Firenze, Italy
Assessing how well a quantum device implements a desired operation is one of the greatest obstacles towards the development of quantum technologies. Current protocols to determine the gate error scale strongly exponential in the number of qubits. We have derived an algebraic framework to identify the minimal information required to perform this task. It is based on characterising only the unitary part of an open system's evolution, reducing the number of required input states to two, independent of the system's size. [1] While this minimal set is impractical for device characterisation, we can construct different reduced sets of states which allow for determining numerical and analytical bounds respectively. We apply these concepts to provide a classification of efficient strategies to determine the average gate error of a quantum gate in terms of the number of required experimental settings, average number of actual measurements, and classical computational resources. [2]
[1] D.M. Reich, G. Gualdi, and C.P. Koch, Phys. Rev. A 88, 042309 (2013)
[2] D.M. Reich, G. Gualdi, and C.P. Koch, Phys. Rev. Lett. 111, 200401 (2013)