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Randomized Benchmarking of Multiqubit Gates



John P. Gaebler, Adam M. Meier, Ting Rei Tan, Ryan S. Bowler, Yiheng Lin, David Hanneke, John D. Jost, Jonathan Home, Emanuel H. Knill, Dietrich G. Leibfried, David J. Wineland


As experimental platforms for quantum information processing continue to mature, characterization of the quality of unitary gates that can be applied to their quantum bits (qubits) becomes essential. Eventually, the quality must be sufficiently high to support arbitrarily long quantum computations. Randomized benchmarking already provides a platform-independent method for assessing the quality of one-qubit rotations. Here we describe an extension of this method to multi-qubit gates. We provide a platform-independent protocol for evaluating the performance of experimental Clifford unitaries, which form the basis of fault-tolerant quantum computing. We implemented the benchmarking procedure with trapped-ion two-qubit phase gates and one-qubit gates and found an error per random two-qubit Clifford unitary of 0.162 ± 0.008. By implementing a second set of sequences with an extra two-qubit phase gate at each step, we extracted an error per phase gate of 0.069 ± 0.017. We conducted these experiments with movable, sympathetically-cooled ions in a multi-zone Paul trap---a system that can in principle be scaled to larger numbers of ions.
Physical Review Letters


Quantum Information, Randomized Benchmarking, Trapped Ions


Gaebler, J. , Meier, A. , , T. , Bowler, R. , Lin, Y. , Hanneke, D. , Jost, J. , Home, J. , Knill, E. , Leibfried, D. and Wineland, D. (2012), Randomized Benchmarking of Multiqubit Gates, Physical Review Letters, [online], (Accessed May 22, 2024)


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Created June 29, 2012, Updated February 19, 2017