Searching for the Quantumness of Gravity

Brian Swingle’s first passion was condensed-matter physics. As a graduate student, he performed calculations to uncover and understand new quantum phases of matter, such as topological insulators and spin liquids. But then Swingle signed up for a string theory class. There he realized that the condensed-matter tools he was developing could be used to answer questions in quantum gravity, the theory that could reconcile Einstein’s general theory of relativity with quantum mechanics. The realization led him to dramatically broaden the scope of his research. Today, Swingle heads a research group at the University of Maryland, where he studies condensed-matter problems and seeks to develop a quantum picture of gravity. In an interview with Physics, Swingle explained his love of quantum gravity, why blue-sky funding is particularly important for researchers in this field, and how spacetime might arise from interactions among entangled qubits.