Entanglement in a Quantum Annealing Processor
Venue
Physical Review X, vol. 4 (2014), pp. 021041
Publication Year
2014
Authors
T. Lanting, A. J. Przybysz, A. Yu. Smirnov, F. M. Spedalieri, M. H. Amin, A. J. Berkley, R. Harris, F. Altomare, S. Boixo, P. Bunyk, N. Dickson, C. Enderud, J. P. Hilton, E. Hoskinson, M. W. Johnson, E. Ladizinsky, N. Ladizinsky, R. Neufeld, T. Oh, I. Perminov, C. Rich, M. C. Thom, E. Tolkacheva, S. Uchaikin, A. B. Wilson, G. Rose
BibTeX
Abstract
Entanglement lies at the core of quantum algorithms designed to solve problems that
are intractable by classical approaches. One such algorithm, quantum annealing
(QA), provides a promising path to a practical quantum processor. We have built a
series of architecturally scalable QA processors consisting of networks of
manufactured interacting spins (qubits). Here, we use qubit tunneling spectroscopy
to measure the energy eigenspectrum of two- and eight-qubit systems within one such
processor, demonstrating quantum coherence in these systems. We present
experimental evidence that, during a critical portion of QA, the qubits become
entangled and entanglement persists even as these systems reach equilibrium with a
thermal environment. Our results provide an encouraging sign that QA is a viable
technology for large-scale quantum computing.
