Alicea, Jason2015-05-212015-05-212015-05https://hdl.handle.net/11299/172315Topological phases of matter often feature boundary physics that naively seems impossible from the viewpoint of systems in one lower dimension. In this talk I will introduce a new class of exotic boundary states known as `composite Dirac liquids’ that can appear at a strongly interacting surface of a 3D electronic topological insulator. Composite Dirac liquids exhibit a gap to all charge excitations but nevertheless feature a single massless Dirac cone built from emergent electrically neutral fermions. These states thus comprise electrical insulators that, interestingly, retain thermal properties similar to those of the non-interacting topological insulator surface. I will show how gapping the neutral fermions via Cooper pairing naturally recovers symmetric non-Abelian surface topological orders captured recently in several works.enFTPISymmetriesPresentation