Experimental setup for the combined study of spin ensembles and superconducting quantum circuits

We demonstrate magnetic crosstalk suppression by more than eight orders of magnitude in a cryogenic hybrid platform that combines a spin-ensemble sample volume with a nearby superconducting-qubit sample volume inside a single dilution refrigerator. This level of isolation enables flux-tunable superconducting qubits to operate stably while a superconducting solenoid generates magnetic fields up to 50 mT in the neighboring spin volume. To our knowledge, this is the first cryogenic platform that experimentally demonstrates simultaneous operation of a spin-ensemble magnetic-control unit and a nearby flux-tunable superconducting-qubit unit within a single dilution refrigerator while preserving qubit stability. It comprises two spatially and magnetically decoupled sample volumes inside a single dilution refrigerator: one hosting flux-tunable superconducting qubits and the other - a spin ensemble equipped with a superconducting solenoid generating fields up to 50 mT. We show that several layers of Cryophy® shielding and an additional superconducting aluminum shield suppress magnetic crosstalk by more than eight orders of magnitude, ensuring stability of the qubit’s performance, and simultaneous independent control of spin ensembles. Moreover, the operation of the solenoid adds minimal thermal load on the relevant stages of the dilution refrigerator. Our results enable scalable hybrid quantum architectures with low-loss integration, marking a key step toward scalable hybrid quantum computing platforms.