2D topological matter from a boundary Green's functions perspective: Faddeev-LeVerrier algorithm implementation

Since the breakthrough of twistronics a plethora of topological phenomena in corre-lated systems has appeared. These devices can be typically analyzed in terms of lattice models using Green's function techniques. In this work we introduce a general method to obtain the boundary Green's function of such models taking advantage of the numer-ical Faddeev-LeVerrier algorithm to circumvent some analytical constraints of previous works. We illustrate our formalism analyzing the edge features of a Chern insulator, the Kitaev square lattice model for a topological superconductor and the Checkerboard lat-tice hosting topological flat bands. The efficiency and accuracy of the method is demon-strated by comparison to recursive Green's function calculations.

Automated summary

The study introduces a general method to obtain the boundary Green's function of correlated systems, using a numerical algorithm to circumvent previous analytical constraints. The efficiency and accuracy of the method is demonstrated through analyzing edge features of different models.