Condensed Matter Seminar: Byungmin Kang, UC Berkeley, “Dynamical Confinement-Deconfinement Transitions in Many-body Localized Topological Phases”

Many-body localization (MBL) is a dynamical quantum phase of matter in which the properties of quantum many-body ground states can be extended to highly excited states in the presence of strong disorder. While the existence and the properties of such many-body localized phases are rather well understood in one dimension, much less is known in higher dimensions in which more exotic quantum orders can be realized. In this talk, I will discuss new kind of topological quantum phase transitions in two dimensions. In particular, I will give a universal real-space renormalization group picture of such phase transitions both at zero temperature and in highly excited states and explain the role of topological string operators which create pairs of anyonic quasiparticles. I will also comment on the differences between abelian and non-abelian topological orders and explain to what extent they can be protected far from equilibrium by many-body localization.