 | Hopper, D A; Lauigan, J D; Huang, T -Y; Bassett, L C Real-Time Charge Initialization of Diamond Nitrogen-Vacancy Centers for Enhanced Spin Readout Journal Article Phys. Rev. Applied, 13 , pp. 024016, 2020. @article{Hopper2019, title = {Real-Time Charge Initialization of Diamond Nitrogen-Vacancy Centers for Enhanced Spin Readout}, author = {D A Hopper and J D Lauigan and T -Y Huang and L C Bassett}, url = {https://arxiv.org/abs/1907.08741 https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.13.024016 https://medium.com/penn-engineering/penn-engineers-ensure-quantum-experiments-get-off-to-the-right-start-bbe6f3382cb}, year = {2020}, date = {2020-02-07}, journal = {Phys. Rev. Applied}, volume = {13}, pages = {024016}, abstract = {Selected as an Editor's Suggestion. A common impediment to qubit performance is imperfect state initialization. In the case of the diamond nitrogen-vacancy (NV) center, the initialization fidelity is limited by fluctuations in the defect's charge state during optical pumping. Here, we use real-time control to deterministically initialize the NV center's charge state at room temperature. We demonstrate a maximum charge initialization fidelity of 99.4±0.1% and present a quantitative model of the initialization process that allows for systems-level optimization of the spin-readout signal-to-noise ratio. Even accounting for the overhead associated with the initialization sequence, increasing the charge initialization fidelity from the steady-state value of 75% near to unity allows for a factor-of-two speedup in experiments while maintaining the same signal-to-noise-ratio. In combination with high-fidelity readout based on spin-to-charge conversion, real-time initialization enables a factor-of-20 speedup over traditional methods, resulting in an ac magnetic sensitivity of 1.3 nT/Hz1/2 for our single NV-center spin. The real-time control method is immediately beneficial for quantum sensing applications with NV centers as well as probing charge-dependent physics, and it will facilitate protocols for quantum feedback control over multi-qubit systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Selected as an Editor's Suggestion. A common impediment to qubit performance is imperfect state initialization. In the case of the diamond nitrogen-vacancy (NV) center, the initialization fidelity is limited by fluctuations in the defect's charge state during optical pumping. Here, we use real-time control to deterministically initialize the NV center's charge state at room temperature. We demonstrate a maximum charge initialization fidelity of 99.4±0.1% and present a quantitative model of the initialization process that allows for systems-level optimization of the spin-readout signal-to-noise ratio. Even accounting for the overhead associated with the initialization sequence, increasing the charge initialization fidelity from the steady-state value of 75% near to unity allows for a factor-of-two speedup in experiments while maintaining the same signal-to-noise-ratio. In combination with high-fidelity readout based on spin-to-charge conversion, real-time initialization enables a factor-of-20 speedup over traditional methods, resulting in an ac magnetic sensitivity of 1.3 nT/Hz1/2 for our single NV-center spin. The real-time control method is immediately beneficial for quantum sensing applications with NV centers as well as probing charge-dependent physics, and it will facilitate protocols for quantum feedback control over multi-qubit systems. |
Our paper on real-time control is selected as an Editor’s suggestion in Phys. Rev. Applied
| Real-Time Charge Initialization of Diamond Nitrogen-Vacancy Centers for Enhanced Spin Readout Journal Article Phys. Rev. Applied, 13 , pp. 024016, 2020. |