Demonstration of Robust Quantum Gate Tomography via Randomized Benchmarking
Abstract
Typical quantum gate tomography protocols struggle with a self-consistency problem: the gate operation cannot be reconstructed without knowledge of the initial state and final measurement, but such knowledge cannot be obtained without well-characterized gates. A recently proposed technique, known as randomized benchmarking tomography (RBT), sidesteps this self-consistency problem by designing experiments to be insensitive to preparation and measurement imperfections. We implement this proposal in a superconducting qubit system, using a number of experimental improvements including implementing each of the elements of the Clifford group in single `atomic' pulses and custom control hardware to enable large overhead protocols. We show a robust reconstruction of several single-qubit quantum gates, including a unitary outside the Clifford group. We demonstrate that RBT yields physical gate reconstructions that are consistent with fidelities obtained by randomized benchmarking.
Cite
@article{arxiv.1505.06686,
title = {Demonstration of Robust Quantum Gate Tomography via Randomized Benchmarking},
author = {Blake R. Johnson and Marcus P. da Silva and Colm A. Ryan and Shelby Kimmel and Jerry M. Chow and Thomas A. Ohki},
journal= {arXiv preprint arXiv:1505.06686},
year = {2015}
}