Notes

subsection*{Source code}
begin{verbatim}
(set! num-bands 4) ;sets the number of bands we need to analyse
(set! geometry-lattice (make lattice (size 1 1 no-size) ;lattice size in z direction to no-size creates a 2D plane
(basis1 (/(sqrt 3) 2) 0.5)
(basis2 (/(sqrt 3) 2) -0.5))) ;change the vectors along which analysis is done
(set! default-material (make dielectric (epsilon 8.7))) ;sets default dielectric constant as 8.7
(set! geometry (list (make cylinder
(center 0 0 0) (radius 0.35) (height infinity)
(material (make dielectric (epsilon 1))))))
(set! k-points (list (vector3 0 0 0) ;Gamma
(vector3 0 0.5 0) ;M
(vector3 (/ -3) (/ 3) 0) ;K
(vector3 0 0 0))) ;Gamma
(set! k-points (interpolate 4 k-points)) ;creates additional 4 points where analysis is done spaced equally betweenthe four reciprocal lattice vectors
(set! resolution 32)
(run-tm output-at-kpoint (vector3 (/ -3) (/ 3) 0)
fix-efield-phase output-efield-z))
(run-te output-at-kpoint (vector3 (/ -3) (/ 3) 0)
fix-hfield-phase output-hfield-z)
(run display-group-velocities)
end{verbatim}