Oral: Performance of high kinetic-inductance planar superconducting resonators in large magnetic fields

Thin film materials with high kinetic-inductance are a valuable asset for superconducting quantum circuits and hybrid architectures. These disordered supercondutors boast increased critical temperatures and critical magnetic field compared to their pure counterparts. The magnetic field resilience is particularly interesting as it can be an important tool for a variety of high frequency superconducting devices, as magnetic field degrade resonator performance by creating dissipative channels, in turn suppressing supercondcutivity.

In this work, we focus on superconducting resonators fabricated from NbN and granular aluminum (grAl), both disordered superconductors that offer higher critical magnetic fields and critical temperatures. These materials enable higher kinetic inductance and impedance, leading to stronger coupling rates. We study the performance of resonators in optimal conditions as well as in varying magnetic fields, comparing their respective evolution of quality factors under different geometries. Special attention is given also concerning the fabrication of such thin films.