QUROPE Quantum Information Processing and Communication in Europe

The Quantronics group at SOLID partner CEA have recently published a paper in Physical Review Letters in wihch they measure the quantum fluctuations of a pumped nonlinear resonator using a superconducting artificial atom as an in situ probe. The qubit excitation spectrum provided access to the frequency and amount of excitation of the intracavity field fluctuations, from which we infer its effective temperature. These quantities were found to be in agreement with theoretical predictions; in particular, the group experimentally observed the phenomenon of quantum heating.