## Files in this item

FilesDescriptionFormat

application/pdf

RAMAMURTHY-DISSERTATION-2019.pdf (3MB)
(no description provided)PDF

## Description

 Title: Patterns of electro-magnetic response in topological semi-metals Author(s): Ramamurthy, Srinidhi T. Director of Research: Hughes, Taylor L. Doctoral Committee Chair(s): Phillips, Philip W. Doctoral Committee Member(s): Cooper, S. Lance; Leigh, Robert G. Department / Program: Physics Discipline: Physics Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: Ph.D. Genre: Dissertation Subject(s): Topological physics, Topological semi-metals, Electromagnetic response. Abstract: 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. Issue Date: 2019-01-07 Type: Text URI: http://hdl.handle.net/2142/104736 Rights Information: Copyright 2019 Srinidhi Ramamurthy Date Available in IDEALS: 2019-08-23 Date Deposited: 2019-05
﻿