The Physics Department congratulates Xiaoliang Qi, who was selected as one of five recipients of the prestigious Simons Investigator Award in Physics for 2018. Simons Investigators are outstanding theoretical scientists who receive research support from the foundation, enabling them to undertake the long-term study of fundamental questions. Xiaoliang's recent work focuses on the role of quantum entanglement in quantum many-body physics and quantum gravity. He helped relate holographic duality with tensor networks, which provide a geometrical representation of quantum many-body states. His earlier work developed the theory of topological states of matter, and pointed out the relationship between topological insulators in three spatial dimensions and axion electrodynamics.