[Colloquium]Cellular automata and dynamical quantum matter

Margarita Davydova, Caltech

Title: Cellular automata and dynamical quantum matter

Abstract: One of the first facts taught in a solid state physics class is that classical ordered phases of matter, such as magnets, cannot exist in one dimension. However, for systems inherently out of equilibrium, such as ones ruled by a cellular automaton, the picture is very different. It was famously shown by Peter Gács that one-dimensional classical magnets and even emergent life-like processes as well as universal computing become possible, all from local interactions! Unfortunately, his cellular automaton is so complicated that very few understand it. What makes matters worse is that when trying to build a quantum computer, we are facing a very closely related problem! I will explain why, and will share a story of how cellular automata helped us make progress towards a 25-year-old open problem in quantum computation.