2013/09/26 by T. H. Taminiau, J. Cramer, T. van der Sar +2 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1038/nnano.2014.2
published as Nature Nanotech. 9, 171 (2014) · V2: Revised to add a reference to simultaneous related work (arXiv:1309.6424)
arxiv created 2013/09/26 · arxiv updated 2014/03/17
Quantum registers of nuclear spins coupled to electron spins of individual solid-state defects are a promising platform for quantum information processing. Pioneering experiments selected defects with favourably located nuclear spins having particularly strong hyperfine couplings. For progress towards large-scale applications, larger and deterministically available nuclear registers are highly desirable. Here we realize universal control over multi-qubit spin registers by harnessing abundant weakly coupled nuclear spins. We use the electron spin of a nitrogen-vacancy centre in diamond to selectively initialize, control and read out carbon-13 spins in the surrounding spin bath and construct high-fidelity single- and two-qubit gates. We exploit these new capabilities to implement a three-qubit quantum-error-correction protocol and demonstrate the robustness of the encoded state against applied errors. These results transform weakly coupled nuclear spins from a source of decoherence into a reliable resource, paving the way towards extended quantum networks and surface-code quantum computing based on multi-qubit nodes.