Microwave Photons Move Out of Equilibrium

Isolated systems that don’t exchange energy with the “outside world” are the easiest to study and control. But most real systems are decidedly not in isolation, nor are they in equilibrium. These include turbulent waves, earthquakes, and the rapidly cooled metal alloys and plastics used in manufacturing. Even richer physics lies in quantum systems that are out of equilibrium, particularly those in which interactions between multiple quantum objects is important. Such systems are difficult to describe theoretically, but investigating them could shed light on fundamental questions about how quantum systems thermalize [1] and the formation of the early Universe. Long term, studying these systems could open new avenues of research in quantum field theory and the quantum simulation of atomic and molecular chemistry.