---

After the experimental realization of graphene by Novoselov and Geim in 2004, for which they were awarded the Nobel Prize to in 2010, the scattering theory of two-dimensional massless Dirac fermions has become relevant because of its role in understanding graphene's transport properties. The latter motivated Jhih-Sheng Wu and Michael M. Fogler to study the problem of scattering on a circular step-like potential barrier, which is assumed to be a model for a circular cluster of charged impurities. The aim of the talk is to make an overview of some main aspects of their recent article Scattering of two-dimensional massless Dirac electrons by a circular potential barrier [1]. In this publication the scattering problem was treated with respect to the values of two parameters, X and rho, characterizing the size and the strength of the barrier, respectively. For each combination of X and rho a suitable tool was found for studying the scattering problem. One of the article's conclusions is the fact that formation of circular clusters increases the conductivity compared to the case of randomly distributed impurities. [1] Jhih-Sheng Wu and Michael M. Fogler, Scattering of two-dimensional massless Dirac electrons by a circular potential barrier, arXiv: 1410.0272v1 1 Oct 2014.

---

Andrey Bolotnikov, Duesseldorf
Seminar room TP 0.03
Contact: Maria Hermanns