Vincent Jouanny

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.
arxiv pdf

Observation of two-mode squeezing in a traveling wave parametric amplifier

  1. Martina Esposito,
  2. Arpit Ranadive,
  3. Luca Planat,
  4. Sebastian Leger,
  5. Dorian Fraudet,
  6. Vincent Jouanny,
  7. Olivier Buisson,
  8. Wiebke Guichard,
  9. Cécile Naud,
  10. José Aumentado,
  11. Florent Lecocq,
  12. and Nicolas Roch
Traveling wave parametric amplifiers (TWPAs) have recently emerged as essential tools for broadband near quantum-limited amplification. However, their use to generate microwave quantum
states still misses an experimental demonstration. In this letter, we report operation of a TWPA as a source of two-mode squeezed microwave radiation. We demonstrate broadband entanglement generation between two modes separated by up to 400 MHz by measuring logarithmic negativity between 0.27 and 0.51 and collective quadrature squeezing below the vacuum limit between 1.5 and 2.1 dB. This work opens interesting perspectives for the exploration of novel microwave photonics experiments with possible applications in quantum sensing and continuous variable quantum computing.
arxiv pdf