High-kinetic inductance NbN films for high-quality compact superconducting resonators

  1. Simone Frasca,
  2. Ivo Nikolaev Arabadzhiev,
  3. Sebastien Yves Bros de Puechredon,
  4. Fabian Oppliger,
  5. Vincent Jouanny,
  6. Roberto Musio,
  7. Marco Scigliuzzo,
  8. Fabrizio Minganti,
  9. Pasquale Scarlino,
  10. and Edoardo Charbon
Niobium nitride (NbN) is a particularly promising material for quantum technology applications, as entails the degree of reproducibility necessary for large-scale of superconducting
circuits. We demonstrate that resonators based on NbN thin films present a one-photon internal quality factor above 105 maintaining a high impedance (larger than 2kΩ), with a footprint of approximately 50×100 μm2 and a self-Kerr nonlinearity of few tenths of Hz. These quality factors, mostly limited by losses induced by the coupling to two-level systems, have been maintained for kinetic inductances ranging from tenths to hundreds of pH/square. We also demonstrate minimal variations in the performance of the resonators during multiple cooldowns over more than nine months. Our work proves the versatility of niobium nitride high-kinetic inductance resonators, opening perspectives towards the fabrication of compact, high-impedance and high-quality multimode circuits, with sizable interactions.