Interplay between kinetic inductance, nonlinearity and quasiparticle dynamics in granular aluminum MKIDs

26 Jul 2019, 12:30
15m
Auditorium G. Testori (Milano)

Auditorium G. Testori

Milano

Piazza Città di Lombardia, 1, 20124 Milano MI
Oral Presentation Low Temperature Detector fabrication techniques and materials Orals LM 003

Speaker

Francesco Valenti (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany; Institut für Prozessdatenverarbeitung und Elektronik, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany)

Description

Microwave kinetic inductance detectors (MKIDs) are thin film, cryogenic, superconducting resonators. Incident Cooper pair-breaking radiation increases their kinetic inductance, thereby measurably lowering their resonant frequency. For a given resonant frequency, the highest MKID responsivity is obtained by maximizing the kinetic inductance fraction $\alpha$. However, in circuits with $\alpha$ close to unity, the low supercurrent density reduces the maximum number of readout photons before bifurcation due to self-Kerr non-linearity, therefore setting a bound for the maximum $\alpha$ before the noise equivalent power (NEP) starts to increase. By fabricating granular aluminum MKIDs with different resistivities, we effectively sweep their kinetic inductance from tens to several hundreds of pH per square. We find a NEP minimum in the range of $30\; \text{aW}/\sqrt{\text{Hz}}$ at $\alpha \approx 0.9$, which results from a trade-off between the onset of non-linearity and a non-monotonic dependence of the noise spectral density versus resistivity.

Student (Ph.D., M.Sc. or B.Sc.) Y
Less than 5 years of experience since completion of Ph.D N

Primary author

Francesco Valenti (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany; Institut für Prozessdatenverarbeitung und Elektronik, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany)

Co-authors

Fabio Henriques (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany) Gianluigi Catelani (JARA Institute for Quantum Information (PGI-11), Forschungszentrum Jülich, 52425 Jülich, Germany) Nataliya Maleeva (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany) Lukas Grünhaupt (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany) Uwe von Lüpke (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany) Sebastian T. Skacel (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany ; Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany) Patrick Winkel (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany) Alexander Bilmes (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany) Alexey V. Ustinov (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany ; Russian Quantum Center, National University of Science and Technology MISIS, 119049 Moscow, Russia ) Johannes Goupy (Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France) Martino Calvo (Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France) Alain Benoît (Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France) Florence Levy-Bertrand (Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France) Alessandro Monfardini (Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France) Ioan M. Pop (Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany ; Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany)

Presentation Materials