Coulomb Interactions in Weyl Semimetals
We propose to employ a novel simulation technique, known as Diagrammatic Monte Carlo (Diag MC) in order to study the effects of coulomb interactions in the Weyl Semimetals (WSM’s). These materials are currently attracting enormous interest as a testbed for phenomena originally conjectured in the context of high energy physics, like Weyl and Majorana fermions. However, they also display new and poorly un- derstood emergent phenomena such as novel superconductivity and as of today the strongest magnetoresistance known in any material . Previous work on this topic was conducted mainly in the context of noninteracting theory, with a small number of exceptions where interactions were taken into account via for example diagrammatic expansions to first order or other forms of approximations. Our intention is to use state of the art simulation techniques to obtain exact and unbiased results for the effects of coulomb interactions in WSM’s, in particular focusing on interplay between interactions and anisotropy. The proposed research will be an integral part of the Swedish Research Council project "Tilted Weyl Fermions" that is lead by Emil J. Bergholtz.  M. N. Ali, J. Xiong, S. Flynn, J. Tao, Q. D. Gibson, L. M. Schoop, T. Liang, N. Haldolaarachchige, M. Hirschberger, N. P. Ong, et al., Nature 514, 205 (2014), URL http://dx.doi. org/10.1038/nature13763.