Topological semimetals are gapless states of matter which have robust and unique electromagnetic responses and surface states. In this thesis, we consider semimetals which have point like Fermi surfaces in various spatial dimensions $D=1,2,3$ which naturally occur in the transition between $n$th order weak topological insulators and a trivial insulating phase. These semimetals include those of Dirac and Weyl type. We construct these phases by layering strong topological insulator phases in lower dimensions. This perspective helps us understand their effective response field theory, which is generally characterized by a $n$-form which represents a source of Lorentz violation and can be read off from the location of the singular points in momentum space and the helicities/chiralities of the singularities. We motivate and derive effective response actions for the 2D and 3D Dirac semi-metals, the Weyl semimetal, the 3D line node semi-metal and the 3D mirror protected topological crystalline insulator.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
