TY - JOUR T1 - Demonstration of Robust Quantum Gate Tomography via Randomized Benchmarking JF - New Journal of Physics Y1 - 2015 A1 - Blake R. Johnson A1 - Marcus P. da Silva A1 - Colm A. Ryan A1 - Shelby Kimmel A1 - Jerry M. Chow A1 - Thomas A. Ohki AB - 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. VL - 17 U4 - 113019 UR - http://arxiv.org/abs/1505.06686 CP - 11 U5 - 10.1088/1367-2630/17/11/113019 ER - TY - JOUR T1 - Robust Extraction of Tomographic Information via Randomized Benchmarking JF - Physical Review X Y1 - 2014 A1 - Shelby Kimmel A1 - Marcus P. da Silva A1 - Colm A. Ryan A1 - Blake R. Johnson A1 - Thomas Ohki AB - We describe how randomized benchmarking can be used to reconstruct the unital part of any trace-preserving quantum map, which in turn is sufficient for the full characterization of any unitary evolution, or more generally, any unital trace-preserving evolution. This approach inherits randomized benchmarking's robustness to preparation and measurement imperfections, therefore avoiding systematic errors caused by these imperfections. We also extend these techniques to efficiently estimate the average fidelity of a quantum map to unitary maps outside of the Clifford group. The unitaries we consider include operations commonly used to achieve universal quantum computation in a fault-tolerant setting. In addition, we rigorously bound the time and sampling complexities of randomized benchmarking procedures. VL - 4 UR - http://arxiv.org/abs/1306.2348v1 CP - 1 J1 - Phys. Rev. X U5 - 10.1103/PhysRevX.4.011050 ER -