



01589nas a2200193   4500008004100000245008100041210006900122260001500191300001100206490000700217520100800224100002301232700002501255700001901280700001901299700002001318700002101338856003601359       2015                        eng d00aDemonstration of Robust Quantum Gate Tomography via Randomized  Benchmarking0 aDemonstration of Robust Quantum Gate Tomography via Randomized B  c2015/11/05  a1130190 v173 a  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.
1 aJohnson, Blake, R.1 ada Silva, Marcus, P.1 aRyan, Colm, A.1 aKimmel, Shelby1 aChow, Jerry, M.1 aOhki, Thomas, A.  uhttp://arxiv.org/abs/1505.06686