Description
Mesoscopic cavities with typical sizes of several resonance wavelengths are well-known model systems for investigating complex dynamics. While the breaking of spatial resonator symmetries is typically considered to be the origin of chaotic dynamics, we show that anisotropies, i.e., broken symmetries in momentum space such as the trigonal warping in bilayer graphene, can also cause chaotic particle dynamics. Such anisotropic properties prevent angular momentum to be a conserved quantity, and consequently the angles of incidence and of reflection of a particle trajectory deviate. We take this into account by implementing a hybrid particle tracing algorithm that incorporates the electronic properties of bilayer graphene in a gate-voltage defined cavity and can be easily applied to other materials. We show that the presence of anisotropies induces chaotic dynamics even in circular cavities and illustrate the intricate interplay of cavity shape and Fermi line geometry. In addition, we use Kwant to demonstrate particle-wave correspondence by comparing the tracing results with wave solutions in real space as well as in phase space using the Husimi function.
