DEPARTMENT COLLOQUIUM | Fundamental Bounds in Quantum Transport, From Black Holes to Bad Metals

Electrical transport in unconventional materials such as "bad metals” continues to pose tough challenges for theory. I will argue that a promising approach to understanding the properties of these materials is through the notion of fundamental quantum bounds on certain observables, that can apply independently of the microscopic dynamics. Some evidence for such bounds has come from the study of black holes, which have been argued to be the “most extreme” of all physical systems in various senses that I will discuss. In particular, the diffusion of energy across a black hole event horizon shares important features in common with the transport of energy and change in a bad metal.