Regelmäßige Veranstaltungen
Titel Referent Datum Ort

Garst, Mirlin, Rockstuhl, Schmalian, Shnirman

Montag, 14.00-15.30 Uhr

10-01

Garst, Rockstuhl

Dienstag, 13.00-14.00 Uhr

10-01

Campus Nord, Geb. 425

Freitag, 15.45-17.15 Uhr

Lehmann HS

Gauge theories in relativistic-like condensed-matter systems: Dirac materials and beyond

Seminar über Theoretische Festkörperphysik

Vortragender:

Natália Menezes

Datum:

19.03.2018 14:00

Ort:

Room 10.01, 10th Floor, Bldg. 30.23, KIT Campus South

Zugehörigkeit:

Utrecht University, the Netherlands

Gastgeber:

Dr. Igor Gornyi

Abstract

In this talk I will first discuss examples of how gauge theories, mainly the quantum electromagnetic theory, may be used to describe the low-energy physics of interacting condensed-matter (Dirac-like) systems.
By focusing on lower-dimensional systems, I will discuss the implications of the dimensional mismatch between the electromagnetic field and the electronic current, and how to obtain an effective
(projected) theory. In 2D, such framework is applied to describe interactions in graphene, capturing not only the renormalized behavior of the Fermi velocity, but also the corrections to the spin gyromagnetic factor [1].
In 1D, the projected theory characterizes interactions at the boundary of two-dimensional time-reversal-invariant topological insulators and leads to a non-Fermi liquid phase, known as the helical Luttinger liquid. This framework allows a first principle determination of the Luttinger parameter K in terms of fundamental constants [2].

In a second moment, I will move away from pseudospin-1/2 (Dirac) systems and discuss aspects of the low-energy physics of the Varma phase introduced for cuprates. Within a gauge theory approach, I will show that this system leads to an atypical topological response, i.e. an atypical Hall conductivity [3].

[1] N. Menezes, Van Sergio Alves, E. C. Marino, L. Nascimento, Leandro O. Nascimento and C. Morais Smith, PRB 95, 245138 (2017).
[2] N. Menezes, G. Palumbo and C. Morais Smith, Sci. Rep. 7, 14175 (2017).
[3] N. Menezes, C. Morais Smith and G. Palumbo, PRB 97, 075135 (2018).