"Although no one has achieved this goal yet, we calculate quantum supremacy can be comfortably demonstrated with 49 qubits, a circuit depth exceeding 40, and a two-qubit error below 0.5%," says Kelly. "We believe the experimental demonstration of a quantum processor outperforming a supercomputer would be a watershed moment for our field, and remains one of our key objectives."
If achieved, say the researchers, Bristlecone would then be a compelling proof-of-principle for building larger-scale quantum computers. However, they add, operating a device such as Bristlecone at low system error requires harmony between a full stack of technology ranging from software and control electronics to the processor itself - a feat that requires careful systems engineering over several iterations.
"We are cautiously optimistic that quantum supremacy can be achieved with Bristlecone, and feel that learning to build and operate devices at this level of performance is an exciting challenge!," says Kelly. "We look forward to sharing the results and allowing collaborators to run experiments in the future."
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