# Microwave properties of superconductors close to SIT

## TL;DR

This paper develops a theoretical framework to understand microwave dissipation in strongly disordered superconductors near the superconductor-insulator transition, highlighting the role of collective modes as a source of noise.

## Contribution

It introduces a new theory of collective modes in disordered superconductors near SIT and analyzes their impact on microwave dissipation and noise.

## Key findings

- Collective modes become significant sources of dissipation near SIT.
- Disorder level influences the spectrum of collective modes.
- High kinetic inductance is associated with proximity to SIT.

## Abstract

Strongly disordered pseudogapped superconductors are expected to display arbitrary high values of kinetic inductance close to superconductor-insulator transition (SIT) that makes them attractive for the implementation of dissipationless superinductance. We develop the theory of the collective modes in these superconductors and discuss associated dissipation at microwave frequencies. We obtain the collective mode spectra dependence on the disorder level and conclude that collective modes become relevant source of dissipation and noise in the far vicinity of SIT.