This paper concerns a boundary integral formulation for the two-dimensional massive
Dirac equation. The mass term is assumed to jump across a one-dimensional
interface, which models a transition between two insulating materials. This
jump induces surface waves that propagate outward along the interface but
decay exponentially in the transverse direction. After providing a derivation
of our integral equation, we prove that it has a unique solution for almost
all choices of parameters using holomorphic perturbation theory. We then
extend these results to a Dirac equation with two interfaces. Finally, we
implement a fast numerical method for solving our boundary integral equations
and present several numerical examples of solutions and scattering effects.
Keywords
Dirac equation, topological insulators, boundary integral
formulation, fast algorithms