Ozgur thank you for the dissertation and your quick reply. Here is a 2D triangular lattice Si W1 PCW mpb code with r=0.25a air holes.When I grep "tefreqs", I see the guided bands taking place of each other where they intersect (in the dispersion graph).
Thank you in advance. Regards, Fulya --------------------------------------------------------------- (define-param r0 0.25) ;radius of holes (define nSi 3.4) ;set refractive index of silicon (define-param index-slab nSi) ;default Silicon (define-param index-holes 1) (define hole-material (make dielectric (epsilon (expt index-holes 2)))) (define slab-material (make dielectric (epsilon (expt index-slab 2)))) (set! default-material slab-material) (print "Default material set to " default-material "\n") (define-param u 3) (define-param w 1) (set! geometry-lattice (make lattice (size 1 (+ (* (+ u w) (sqrt 3)) 1) no-size) (basis1 1 0 0) (basis2 0 1 0) (basis3 0 0 1))) (define-param res 32) (set! resolution res) (set! mesh-size 3) (define-param numbands 17) ;number of bands defaults to 30 (set! num-bands numbands) (print "resolution = " resolution "\n") (print "mesh size = " mesh-size "\n") (print "number of bands = " num-bands "\n") (define holes-list-first-row-a (list (make cylinder ;1st row (center 0.5 (* -0.5 (+ 0 w) (sqrt 3)) 0) (radius r0) (height infinity) (material hole-material)) )) (define holes-list-first-row-b (list (make cylinder ;first row (center 0.5 (* 0.5 (+ 0 w) (sqrt 3)) 0) (radius r0) (height infinity) (material hole-material)) )) ;define second row with shift s2,p2,r2 (define holes-list-second-row-a (list (make cylinder ;2nd row (center 0 (* -0.5 (+ 1 w) (sqrt 3)) 0) (radius r0) (height infinity) (material hole-material)) )) (define holes-list-second-row-b (list (make cylinder ;second row (center 0 (* 0.5 (+ 1 w) (sqrt 3)) 0) (radius r0) (height infinity) (material hole-material)) )) ;define second row with shift s3,p3,r0 (define holes-list-third-row-a (list (make cylinder ;3rd row (center 0.5 (* -0.5 (+ 2 w) (sqrt 3)) 0) (radius r0) (height infinity) (material hole-material)) )) (define holes-list-third-row-b (list (make cylinder ;third row (center 0.5 (* 0.5 (+ 2 w) (sqrt 3)) 0) (radius r0) (height infinity) (material hole-material)) )) ;define remaining rows (define holes-list-remaining-rows-a (list (make cylinder ;4th row (center 0 (* -0.5 (+ 3 w) (sqrt 3)) 0) (radius r0) (height infinity) (material hole-material)))) (define holes-list-remaining-rows-b (list (make cylinder ;4th row (center 0 (* 0.5 (+ 3 w) (sqrt 3)) 0) (radius r0) (height infinity) (material hole-material)))) (define holes-list holes-list-first-row-a) (set! holes-list (append holes-list holes-list-first-row-b)) (set! holes-list (append holes-list holes-list-second-row-a)) (set! holes-list (append holes-list holes-list-second-row-b)) (set! holes-list (append holes-list holes-list-third-row-a)) (set! holes-list (append holes-list holes-list-third-row-b)) (set! holes-list (append holes-list holes-list-remaining-rows-a)) (set! holes-list (append holes-list holes-list-remaining-rows-b)) (set! geometry holes-list) (define-param Ks 0) (define-param Ke 0.5) (define Kstart (vector3 Ks 0 0)) (define Kend (vector3 Ke 0 0)) (define-param Kinterp 48) ;number of k-points (set! k-points (interpolate Kinterp (list Kstart Kend))) (run-te)
_______________________________________________ mpb-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss
