Quantum thermalization through entanglement in an isolated many-body system

The concept of entropy is fundamental to thermalization, yet appears at odds with basic principles in quantum mechanics. Statistical mechanics relies on the maximization of entropy for a system at thermal equilibrium. However, an isolated many-body system initialized in a pure state will remain pure during Schr\"{o}dinger evolution, and in this sense has static, zero entropy. The underlying role of quantum mechanics in many-body physics is then...