Achieving high cooperativity between a semiconductor defect center and a superconducting resonator

Defect centers in semiconductors, such as the NV^- center in diamond, are promising candidates for network-based quantum technologies. In addition to optical transitions, these emitters also possess spin degrees of freedom which can serve as long lived quantum memories. However, this spin degree of freedom is often difficult to utilize due to its weak interaction with the electromagnetic field. To overcome this problem, here we propose to strongly couple a single defect’s spin degree of freedom to a microwave resonator. Borrowing techniques from the field of superconducting microwave circuits, this resonator is engineered to keep loss low, while at the same time enhancing the magnetic field at the defect location to increase coupling. Successful implementation of this proposal will enable coherent protocols in quantum information and transduction.