Coherent Coupled Qubits for Quantum Annealing
Steven J. Weber, Gabriel Samach, David J. Hover, Simon Gustavsson, David K. Kim, Alexander J. Melville, Danna Rosenberg, Adam Sears, Fei Yan, Jonilyn Yoder, William D. Oliver, Andrew J. Kerman · Physical Review Applied · 2017
Although quantum annealing has received considerable interest as a potential computing paradigm, it has not met the key criterion of improved scaling over classical methods. Qubit coherence is currently a major limitation. Starting from a detailed theoretical understanding of the system, the authors demonstrate tunably coupled flux qubits with a circuit geometry similar to those used in existing annealers, but with coherence times that are roughly two orders of magnitude longer. Their design concepts are not limited to superconducting qubits, and could be generalized to other types being considered for quantum annealing.