TY  - JOUR
AU  - Valenti, Francesco
AU  - Henriques, Fabio
AU  - Catelani, Gianluigi
AU  - Maleeva, Nataliya
AU  - Grünhaupt, Lukas
AU  - von Lüpke, Uwe
AU  - Skacel, Sebastian T.
AU  - Winkel, Patrick
AU  - Bilmes, Alexander
AU  - Ustinov, Alexey V.
AU  - Goupy, Johannes
AU  - Calvo, Martino
AU  - Benoît, Alain
AU  - Levy-Bertrand, Florence
AU  - Monfardini, Alessandro
AU  - Pop, Ioan M.
TI  - Interplay Between Kinetic Inductance, Nonlinearity, and Quasiparticle Dynamics in Granular Aluminum Microwave Kinetic Inductance Detectors
JO  - Physical review applied
VL  - 11
IS  - 5
SN  - 2331-7019
CY  - College Park, Md. [u.a.]
PB  - American Physical Society
M1  - FZJ-2019-03177
SP  - 054087
PY  - 2019
AB  - 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 α. However, in circuits with α close to unity, the low supercurrent density reduces the maximum number of readout photons before bifurcation due to self-Kerr nonlinearity, therefore setting a bound for the maximum α 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 30aW/√Hz at α≈0.9, which results from a trade-off between the onset of nonlinearity and a nonmonotonic dependence of the noise spectral density versus resistivity.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000470891900002
DO  - DOI:10.1103/PhysRevApplied.11.054087
UR  - https://juser.fz-juelich.de/record/863055
ER  -