Spin Dynamics of a Solid-State Qubit in Proximity to a Superconductor

A broad effort is underway to understand and harness the interaction between superconductors and spin-active color centers with an eye on hybrid quantum devices and novel imaging modalities of superconducting materials. Most work, however, overlooks the interplay between either system and the environment created by the color center host. Here we use a diamond scanning probe to investigate the spin dynamics of a single nitrogen-vacancy (NV) center proximal to a superconducting film. We find that the presence of the superconductor increases the NV spin coherence lifetime, a phenomenon we tentatively rationalize as a change in the electric noise due to a superconductor-induced redistribution of charge carriers near induced redistribution of charge carriers near the NV. We then build on these findings to demonstrate transverse-relaxation-time-weighted imaging of the superconductor film. These results shed light on the dynamics governing the spin coherence of shallow NVs, and promise opportunities for new forms of noise spectroscopy and imaging of superconductors.

Automated summary

A broad effort is being made to understand and utilize the interaction between superconductors and spin-active color centers, with the goal of hybrid quantum devices and novel imaging techniques for superconducting materials. However, most work ignores the interplay between either system and the environment created by the color center host. In this study, a diamond scanning probe is used to investigate the spin dynamics of a single nitrogen-vacancy (NV) center near a superconducting film. The presence of the superconductor is found to increase the NV spin coherence lifetime, which may be attributed to a change in the electric noise caused by a redistribution of charge carriers due to the superconductor. These findings not only shed light on the dynamics of shallow NV spin coherence, but also offer new possibilities for noise spectroscopy and imaging of superconductors.