Excess quasiparticles and their dynamics in the presence of subgap states
Author: Catelani, Gianluigi
Affiliation: Juelich Research Center and Technology Innovation Institute
Type: Contributed Talk
Session: Superconducting quantum devices
Date and Time: 20.07.2026, 18:20 - 18:40
Material inhomogeneities in a superconductor generically lead to broadening of the density of states and to subgap states. The latter are associated with spatial fluctuations of the gap in which quasiparticles can be trapped. Recombination between such localized quasiparticles is hindered by their spatial separation and hence their density could be higher than expectations based on the recombination between mobile quasiparticles. We show here that the recombination between localized and mobile excitations can be efficient at limiting the quasiparticle density. We comment on the significance of our findings for devices such as superconducting resonators and qubits.We find that for typical aluminum devices, the subgap states do not significantly influence the quasiparticle density.