Characterizing crosstalk of superconducting transmon processors
Currently available quantum computing hardware based on superconducting
transmon architectures realizes networks of hundreds of qubits with the
possibility of controlled nearest-neighbor interactions. However, the inherent
noise and decoherence effects of such quantum chips considerably alter basic
gate operations and lead to imperfect outputs of the targeted quantum
computations. In this work, we focus on the characterization of crosstalk
effects which manifest themselves in correlations between simultaneously
executed quantum gates on neighboring qubits. After a short explanation of the
physical origin of such correlations, we show how to efficiently and
systematically characterize the magnitude of such crosstalk effects on an
entire quantum chip using the randomized benchmarking protocol. We demonstrate
the introduced protocol by running it on real quantum hardware provided by IBM
observing significant alterations in gate fidelities due to crosstalk. Lastly,
we use the gained information in order to propose more accurate means to
simulate noisy quantum hardware by devising an appropriate crosstalk-aware
noise model.
Andreas Ketterer Thomas Wellens