Southwest Quantum Information and Technology

Benchmarking a qutrit

Presenting Author: Ian Hincks, Institute for Quantum Computing, Waterloo, Canada
Contributing Author(s): Christopher Granade and David G. Cory

Randomized Benchmarking and related twirling-based protocols have become mainstays in assessing the quality of quantum logic gates. These protocols physically implement symmetrization by unitary groups in such a way as to exponentially reduce the number of parameters describing a gate or gateset down to just a few, including average fidelity or unitarity. In this talk, we provide a holistic account of performing randomized benchmarking on an Nitrogen Vacancy defect in diamond. This quantum system has three controllable energy levels, and several physical characteristics which make it ideal for experimentally studying quantum control and inference. We discuss methodologies of cosine-modulated gate design with numerical optimal control, characterizing Hamiltonian parameters with Bayesian inference, and driving microwave transitions in the non-linear regime of an amplifier. We find a 72-element Clifford subgroup, which is the smallest 2-design sufficient for the randomized benchmarking and unitarity protocols. We show the results of these experiments, emphasizing that rigorous statistical analysis improves the credibility of parameter estimates.

(Session 5 : Thursday from 5:00pm - 7:00pm)