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Universal high-fidelity quantum gates for spin qubits in diamond

MetadataDetails
Publication Date2025-03-21
JournalPhysical Review Applied
AuthorsHanna Bartling, J. Yun, Kai-Niklas Schymik, M. van Riggelen, Luc Enthoven
InstitutionsElement Six (Germany), Delft University of Technology
Citations7

Spins associated to solid-state color centers are a promising platform for investigating quantum computation and quantum networks. Recent experiments have demonstrated multiqubit quantum processors, optical interconnects, and basic quantum error-correction protocols. One of the key open challenges towards larger-scale systems is to realize high-fidelity universal quantum gates. In this work, we design and demonstrate a complete high-fidelity gate set for the two-qubit system formed by the electron and nuclear spin of a nitrogen-vacancy center in diamond. We use gate set tomography (GST) to systematically optimize the gates and demonstrate single-qubit gate fidelities of up to <a:math xmlns:a=ā€œhttp://www.w3.org/1998/Math/MathMLā€ display=ā€œinlineā€ overflow=ā€œscrollā€><a:mn>99.999</a:mn><a:mo stretchy=ā€œfalseā€>(</a:mo><a:mn>1</a:mn><a:mo stretchy=ā€œfalseā€>)</a:mo><a:mi mathvariant=ā€œnormalā€>%</a:mi></a:math> and a two-qubit gate fidelity of <g:math xmlns:g=ā€œhttp://www.w3.org/1998/Math/MathMLā€ display=ā€œinlineā€ overflow=ā€œscrollā€><g:mn>99.93</g:mn><g:mo stretchy=ā€œfalseā€>(</g:mo><g:mn>5</g:mn><g:mo stretchy=ā€œfalseā€>)</g:mo><g:mi mathvariant=ā€œnormalā€>%</g:mi></g:math>. Our gates are designed to decouple unwanted interactions and can be extended to other electron-nuclear spin systems. The high fidelities demonstrated provide opportunities towards larger-scale quantum processing with color-center qubits.