Characterizing the 'arrow of time' in open quantum systems

Even in the strange world of open quantum systems, the arrow of time points steadily forward -- most of the time. A video details new experiments conducted at Washington University in St. Louis that compare the forward and reverse trajectories of superconducting circuits called qubits, and find that they largely tend to follow the second law of thermodynamics. The research is published July 9 in the journal Physical Review Letters.