A "Spins-inside" Quantum Processor

Prof.dr. L.M.K.  Vandersypen

QuTech and Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands

Quantum computation has captivated the minds of many for almost two decades. For most of that time, it was seen mostly as an extremely interesting scientific problem. In the last few years, we have entered a new phase as the belief has grown that a large-scale quantum computer may actually be built. Quantum bits encoded in the spin state of individual electrons in silicon quantum dot arrays, have emerged as a highly promising direction. In this talk, I will outline our vision for a large-scale silicon-based quantum computer and present our progress towards realizing this vision. The building blocks are local 2D quantum registers that are interconnected with on-chip quantum links. We are now able to program two silicon quantum bits to run simple quantum algorithms, shuttle electrons through an array while preserving their spin state, and coherently couple a single spin to a single microwave photon in an on-chip cavity. Finally, we have developed new concepts and techniques that make quantum dot arrays a credible platform for quantum simulation of the Mott-Hubbard model. The progress along these various fronts can lead the way to scalable networks of high-fidelity spin qubit registers for computation and simulation.

References:

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[2] T.A. Baart, T. Fujita, C. Reichl, W. Wegscheider, L.M.K. Vandersypen, Coherent spin-exchange via a quantum mediator, Nature Nanotechnology, 12, 26–30 (2017).
[3] T. Hensgens, T. Fujita, L. Janssen, Xiao Li, C. J. Van Diepen, C. Reichl, W. Wegscheider, S. Das Sarma, L. M. K. Vandersypen, Quantum simulation of a Fermi-Hubbard model using a semiconductor quantum dot array, Nature 548, 70 (2017).
[4] F. Watson, S. G. J. Philips, E. Kawakami, D. R. Ward, P. Scarlino, M. Veldhorst, D. E. Savage, M. G. Lagally, Mark Friesen, S. N. Coppersmith, M. A. Eriksson, L. M. K. Vandersypen, A programmable two-qubit quantum processor in silicon, arXiv:1708.04214
[5] N. Samkharadze, G. Zheng, N. Kalhor, D. Brousse, A. Sammak, U. C. Mendes, A. Blais, G. Scappucci, L. M. K. Vandersypen, Strong spin-photon coupling in silicon, arxiv:1711.02040