Quantum Heating of a nonlinear resonator probed by a superconducting qubit

TL;DR

This paper investigates quantum heating in a pumped nonlinear resonator by using a superconducting qubit as an in-situ probe, confirming theoretical predictions through experimental measurements of quantum fluctuations.

Contribution

It introduces a novel method to measure intracavity quantum fluctuations using a superconducting qubit, demonstrating quantum heating effects in a nonlinear resonator.

Findings

Quantum heating observed experimentally.

Qubit excitation spectrum matches theoretical predictions.

Intracavity field fluctuations characterized in detail.

Abstract

We measure the quantum fluctuations of a pumped nonlinear resonator, using a superconducting artificial atom as an in-situ probe. The qubit excitation spectrum gives access to the frequency and temperature of the intracavity field fluctuations. These are found to be in agreement with theoretical predictions; in particular we experimentally observe the phenomenon of quantum heating.