gftool.surface_gf_zeps

gftool.surface_gf_zeps(z, eps, hopping_nn)

Surface Green’s function for stacked layers.

\[\left(1 - \sqrt{1 - 4 t^2 g_{00}^2}\right)/(2 t^2 g_{00})\]

with \(g_{00} = (z-ϵ)^{-1}\) [odashima2016]. This is in principle the Green’s function for a semi-infinite chain.

Parameters:

z : complex

Green’s function is evaluated at complex frequency z.

eps : float

Eigenenergy (dispersion) for which the Green’s function is evaluated.

hopping_nn : float

Nearest neighbor hopping \(t\) between neighboring layers.

Returns:

surface_gf_zeps : complex

Value of the surface Green’s function

References

[odashima2016]

Odashima, Mariana M., Beatriz G. Prado, and E. Vernek. Pedagogical Introduction to Equilibrium Green’s Functions: Condensed-Matter Examples with Numerical Implementations. Revista Brasileira de Ensino de Fisica 39, no. 1 (September 22, 2016). https://doi.org/10.1590/1806-9126-rbef-2016-0087.