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arXiv · 2208.14671

High Fidelity Control of a Nitrogen-Vacancy Spin Qubit at Room Temperature using the SMART Protocol

Hyma H. Vallabhapurapu·Ingvild Hansen·Chris Adambukulam·Rainer Stohr·Andrej Denisenko·Chih Hwan Yang·Arne Laucht
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Abstract

A practical implementation of a quantum computer requires robust qubits that are protected against their noisy environment. Dynamical decoupling techniques have been successfully used in the past to offer protected high-fidelity gate operations in negatively-charged Nitrogen-Vacancy (NV-) centers in diamond, albeit under specific conditions with the intrinsic nitrogen nuclear spin initialised. In this work, we show how the SMART protocol, an extension of the dressed-qubit concept, can be implemented for continuous protection to offer Clifford gate fidelities compatible with fault-tolerant schemes, whilst prolonging the coherence time of a single NV- qubit at room temperature. We show an improvement in the average Clifford gate fidelity from $0.940\pm0.005$ for the bare qubit to $0.993\pm0.002$ for the SMART qubit, with the nitrogen nuclear spin in a random orientation. We further show a $\gtrsim$ 30 times improvement in the qubit coherence times compared to the bare qubit.

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Hyma H. Vallabhapurapu, Ingvild Hansen, Chris Adambukulam, Rainer Stohr, Andrej Denisenko, Chih Hwan Yang, Arne Laucht. 2022-08-31. High Fidelity Control of a Nitrogen-Vacancy Spin Qubit at Room Temperature using the SMART Protocol. https://doi.org/10.1103/physreva.108.022606

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