Interactions in Weyl semimetals of type I

Abstract

The discovery of graphene opened the way to an intriguing field in condensed matter: that of Dirac materials (DM). In these materials, electrons have a linear dispersion relation, making them a solid-state analoguos of relativistic massless particles. The possible realization of DM in three dimensions has drawed a lot of attention, since these systems are much more stable than their 2D cousins, e.g. graphene. In my research I focus on three dimensional DM and investigate their properties once an additional interaction term is added to the Hamiltonian. This latter has the effect of tilting the characteristic Weyl cones in the momentum space and breaks isotropy. We will investigate whether this symmetry breaking finds a signature in observables that can be measured: to this end we will compute both the optical conductivity and the polarization function in the framework of linear response theory. Finally we will study the role of interactions within the system: using a renormalization group approach we will investigate whether the tilting term brings some differences in the system parameter’s flow.