# Fast control of dissipation in a superconducting resonator

## TL;DR

This paper demonstrates rapid, electrically-controlled tuning of a superconducting resonator's dissipation rate using a quantum-circuit refrigerator, enabling fast reset and potential qubit initialization.

## Contribution

It introduces a method for fast, electrical control of resonator damping using a QCR, achieving significant tunability and rapid operation times.

## Key findings

- Damping rate tunability up to nearly two orders of magnitude
- Operation times as short as 10 nanoseconds
- Potential application for fast qubit initialization

## Abstract

We report on fast tunability of an electromagnetic environment coupled to a superconducting coplanar waveguide resonator. Namely, we utilize a recently-developed quantum-circuit refrigerator (QCR) to experimentally demonstrate a dynamic tunability in the total damping rate of the resonator up to almost two orders of magnitude. Based on the theory it corresponds to a change in the internal damping rate by nearly four orders of magnitude. The control of the QCR is fully electrical, with the shortest implemented operation times in the range of 10 ns. This experiment constitutes a fast active reset of a superconducting quantum circuit. In the future, a similar scheme can potentially be used to initialize superconducting quantum bits.