Demonstration of Robust Quantum Gate Tomography via Randomized Benchmarking

TitleDemonstration of Robust Quantum Gate Tomography via Randomized Benchmarking
Publication TypeJournal Article
Year of Publication2015
AuthorsJohnson, BR, da Silva, MP, Ryan, CA, Kimmel, S, Chow, JM, Ohki, TA
JournalNew Journal of Physics
Date Published2015/11/05

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