Thursday, November 16, 2017 at 10:15am to 11:15am
Physical Sciences Building, 416
245 East Avenue
Aavishkar Patel, Department of Physics, Harvard University, Cambridge, MA, will present seminar. Professor Eun-Ah Kim, host.
Seminar Title: Many-body quantum chaos in correlated metals
Abstract: I will describe computations of parameters characterizing many-body quantum chaos in two different examples of interacting quantum metals. These parameters describe “scrambling”, i.e. the spread of quantum information across all of the degrees of freedom in a system leading to a loss of memory of the initial state, a process that is essential for thermalization. The first example consists of a metal with a Fermi surface coupled to a dynamical U(1) gauge field in two spatial dimensions. This is a strongly interacting state of quantum matter without quasiparticles, and is consequently a fast scrambler. The thermal diffusivity of this metal is universally related to the parameters describing scrambling. The second example consists of a weakly interacting electron liquid subject to random potential disorder. Even though the electrons naturally exhibit diffusive motion in this system, quantum information about inelastic electron collisions spreads ballistically with a temperature-dependent velocity. In two spatial dimensions, the Lyapunov exponent parameterizing the rate of scrambling is universally related at weak coupling to the sheet resistivity of this metal