Quantum mechanics is in a position similar to that of relativity a hundred years ago. The Lorentz equations worked in 1905 but no one knew why. Then Einstein came along and pointed out that physics is the same in all inertial frames and that the speed of light was an ultimate limit. This new insight revolutionized physics. It would be wonderful to have an equivalent new insight for quantum mechanics. Today we know the postulates of quantum mechanics and the Schrödinger equation work, but we do not know why.

It is a grand task to understand the foundations of quantum mechanics. There is new hope at present for this task since, for the first time, we can isolate coherent quantum systems from environmental interactions. At present these are small systems, e.g. a few ions, where we can clearly measure entanglement between the particles and preserve it for extended periods of time. Soon we will have much larger isolated quantum systems. What can we learn from these new quantum systems? Why do the new quantum algorithms have their unique quantum power? Why can a quantum simulator work and a classical one fail at levels above 40 fermionic particles? What is the best way to describe the "quantumness" of quantum states?

One interesting set of experiments is the study of the dynamics of entanglement. Entanglement is inevitable in interacting quantum systems. How does entanglement and information flow between an atomic system and a larger system like a molecule as they interact in an isolated system? In the quantum simulation experiments, how does the system come to equilibrium after the interactions are abruptly turned on? These and many other questions concerning quantum measurement and dynamic interactions are not only fascinating, but could possibly lead to breakthroughs in our fundamental understanding of quantum mechanics.

Jean Bellissard, Ken Brown, John Cortese, Michael Chapman, Alex Kuzmich, Chandra Raman, and Dick Slusher