High-fidelity control of a multi-qubit network node in diamond

A powerful approach to realise large-scale quantum computations and simulations is to use quantum networks, which are comprised of a number of multi-qubit nodes connected together by photonic links [1]. The nitrogen vacancy (NV) centre in diamond is a promising platform for building such networks, as it combines optical entanglement links through its electron spin [2,3] with long-lived nuclear spin qubits that can store and process quantum information [4,5]. A key requirement is to realise high-fidelity control over multi-qubit nuclear spin registers within each node.

I will present our experimental demonstration of a novel method to perform selective electron-nuclear two-qubit gates. The method uses radio frequency pulses resonant with the target nuclear spin interleaved with dynamical decoupling pulses on the electron spin. This has several key advantages compared to previous control methods, allowing more nuclear spins to be addressed and higher gate fidelities to be reached.

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[2] Bernien, H. et al. Nature 497, 86-90 (2013)
[3] Hensen, B. et al. Nature 526, 682-686 (2015)
[4] Taminiau, T. H. et al. Nature Nanotechnology 9, 171-176 (2014)
[5] Cramer, J. et al. Nature Communications 7, 11526 (2016)