Speaker
Francesco Valenti
(KIT)
Description
Out of equilibrium quasiparticles (QPs) are a main source of dissipation and noise in superconducting circuits. The generation-recombination
processes of QPs link their dynamics to the phonon dynamics of the circuit and substrate ensemble. We demonstrate that surrounding
granular aluminum resonators with lower gapped aluminum islands increases the internal quality factors of the resonators in the single
photon regime, suppresses the noise, and reduces the rate of observed QP generation events, which we all attribute to phonon trapping.
Primary author
Francesco Valenti
(KIT)
