Inductive losses in quantum devices: limitations and perspectives
Inductive elements with various degrees of nonlinearity play a pivotal role in superconducting quantum devices such as kinetic inductance detectors, parametric amplifiers and quantum bits. Josephson junction arrays implement almost perfect compact inductors, with low dissipation and high characteristic impedance, however, their relatively high nonlinearity and design complexity can be a limiting factor. Granular Aluminum is a disordered superconducting material that bridges the gap between Josephson junction arrays and atomically disordered superconductors, such as Niobium Nitride, Indium Oxide, etc. In this talk I will present the various use cases for granular Aluminum in superconducting quantum electronics, its limitations and some perspectives of improvement. I will also make a parallel with Josephson junction arrays and highlight a striking difference between their inductive losses.