We report the experimental realization of a hybrid quantum circuit combining a superconducting qubit and an ensemble of electronic spins (Fig. a). The qubit, of the transmon type, is coherently coupled to the spin ensemble consisting of nitrogen-vacancy (NV) centers in a diamond crystal via a frequency-tunable superconducting resonator acting…

Superconducting electronic circuits have turned into one of the prime physical systems to investigate quantum optical and atomic physics phenomena in engineered solid state devices. While the on-demand generation and the processing of quantum states on a chip are now routinely achieved with high fidelity, it remains challenging to detect…