Quantum Heating of a Nonlinear Resonator Probed by a Superconducting Qubit
Florian R. Ong, Maxime Boissonneault, F. Mallet, Andrew C. Doherty, Alexandre Blais, D. Vion, Daniel Esteve, Patrice Bertet · Physical Review Letters · 2013
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 amount of excitation of the intracavity field fluctuations, from which we infer its effective temperature. These quantities are found to be in agreement with theoretical predictions; in particular, we experimentally observe the phenomenon of quantum heating.