Magnetic field resilient high kinetic inductance superconducting niobium nitride coplanar waveguide resonators

We characterize niobium nitride (NbN) lambda / 2 coplanar waveguide resonators, which were fabricated from a 10-nm-thick film on silicon dioxide grown by sputter deposition. For films grown at 180 degrees C, we report a superconducting critical temperature of 7.4K associated with a normal square resistance of 1 k Omega, leading to a kinetic inductance of 192 pH/?. We fabricated resonators with a characteristic impedance up to 4.1 k Omega and internal quality factors Q i > 10 4 in the single photon regime at zero magnetic field. Moreover, in the many photon regime, the resonators present a high magnetic field resilience with Q i > 10 4 in a 6T in-plane magnetic field and in a 300mT out-of-plane magnetic field. These findings make such resonators a compelling choice for circuit quantum electrodynamics experiments involving quantum systems with small electric dipole moments operated in finite magnetic fields.

Automated summary

NbN resonators exhibit high internal quality factors under different magnetic field conditions, making them a compelling choice for circuit quantum electrodynamics experiments involving quantum systems with small electric dipole moments.