a question about use 3d supercell calculate band of photonic crystal slab ?

[email protected] Mon, 20 Apr 2009 22:54:43 +0800
Newsgroups	gmane.comp.science.photonic-bands
Message-ID	<[email protected]>
Dear&nbsp;Prof.&nbsp;Johnson&nbsp;and&nbsp;mpb&nbsp;users:
&nbsp;&nbsp;
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I&nbsp;calculated&nbsp;the&nbsp;mode&nbsp;of&nbsp;slab&nbsp;by&nbsp;using&nbsp;the&nbsp;ctl&nbsp;example&nbsp;file&nbsp;,which&nbsp;is&nbsp;hole-slab.ctl&nbsp;.&nbsp;&nbsp;I&nbsp;saw&nbsp;that&nbsp;the&nbsp;second&nbsp;band&nbsp;and&nbsp;the&nbsp;third&nbsp;band&nbsp;is&nbsp;overlap&nbsp;and&nbsp;&nbsp;the
&nbsp;fourth&nbsp;band&nbsp;and&nbsp;the&nbsp;fifth&nbsp;band&nbsp;is&nbsp;overlap&nbsp;.&nbsp;but&nbsp;the&nbsp;first&nbsp;one&nbsp;isalone&nbsp;.I&nbsp;think&nbsp;the&nbsp;true&nbsp;case&nbsp;is&nbsp;&nbsp;that&nbsp;the&nbsp;second&nbsp;band&nbsp;and&nbsp;the&nbsp;third&nbsp;band&nbsp;belong&nbsp;to&nbsp;the&nbsp;same&nbsp;&nbsp;band&nbsp;,
&nbsp;and&nbsp;the&nbsp;fourth&nbsp;band&nbsp;&nbsp;and&nbsp;the&nbsp;fifth&nbsp;band&nbsp;belong&nbsp;to&nbsp;another&nbsp;one&nbsp;.&nbsp;the&nbsp;split&nbsp;of&nbsp;&nbsp;the&nbsp;band&nbsp;arise&nbsp;from&nbsp;the&nbsp;useing&nbsp;of&nbsp;supercell&nbsp;.&nbsp;Is&nbsp;the&nbsp;opinion&nbsp;right&nbsp;?&nbsp;are&nbsp;there&nbsp;any&nbsp;
means&nbsp;to&nbsp;gain&nbsp;a&nbsp;band&nbsp;without&nbsp;split&nbsp;?
&nbsp;

the&nbsp;code&nbsp;

(define-param&nbsp;h&nbsp;0.5)&nbsp;;&nbsp;the&nbsp;thickness&nbsp;of&nbsp;the&nbsp;slab
(define-param&nbsp;eps&nbsp;12.0)&nbsp;;&nbsp;the&nbsp;dielectric&nbsp;constant&nbsp;of&nbsp;the&nbsp;slab
(define-param&nbsp;loweps&nbsp;1.0)&nbsp;;&nbsp;the&nbsp;dielectric&nbsp;constant&nbsp;of&nbsp;the&nbsp;substrate
(define-param&nbsp;r&nbsp;0.3)&nbsp;;&nbsp;the&nbsp;radius&nbsp;of&nbsp;the&nbsp;holes
(define-param&nbsp;supercell-h&nbsp;4)&nbsp;;&nbsp;height&nbsp;of&nbsp;the&nbsp;supercell
;&nbsp;triangular&nbsp;lattice&nbsp;with&nbsp;vertical&nbsp;supercell:
(set!&nbsp;geometry-lattice&nbsp;(make&nbsp;lattice&nbsp;(size&nbsp;1&nbsp;1&nbsp;supercell-h)
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(basis1&nbsp;(/&nbsp;(sqrt&nbsp;3)&nbsp;2)&nbsp;0.5)
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(basis2&nbsp;(/&nbsp;(sqrt&nbsp;3)&nbsp;2)&nbsp;-0.5)))
(set!&nbsp;geometry
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(list&nbsp;(make&nbsp;block&nbsp;(material&nbsp;(make&nbsp;dielectric&nbsp;(epsilon&nbsp;loweps)))
&nbsp;&nbsp;&nbsp;&nbsp;(center&nbsp;0&nbsp;0&nbsp;(*&nbsp;0.25&nbsp;supercell-h))
&nbsp;&nbsp;&nbsp;&nbsp;(size&nbsp;infinity&nbsp;infinity&nbsp;(*&nbsp;0.5&nbsp;supercell-h)))
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(make&nbsp;block&nbsp;(material&nbsp;(make&nbsp;dielectric&nbsp;(epsilon&nbsp;eps)))
&nbsp;&nbsp;&nbsp;&nbsp;(center&nbsp;0)&nbsp;(size&nbsp;infinity&nbsp;infinity&nbsp;h))
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(make&nbsp;cylinder&nbsp;(material&nbsp;air)
&nbsp;&nbsp;&nbsp;&nbsp;(center&nbsp;0)&nbsp;(radius&nbsp;r)&nbsp;(height&nbsp;supercell-h))))
;&nbsp;1st&nbsp;Brillouin&nbsp;zone&nbsp;of&nbsp;a&nbsp;triangular&nbsp;lattice:
(define&nbsp;Gamma&nbsp;(vector3&nbsp;0&nbsp;0&nbsp;0))
(define&nbsp;M&nbsp;(vector3&nbsp;0&nbsp;0.5&nbsp;0))
(define&nbsp;K&nbsp;(vector3&nbsp;(/&nbsp;-3)&nbsp;(/&nbsp;3)&nbsp;0))
(define-param&nbsp;only-K&nbsp;false)&nbsp;;&nbsp;run&nbsp;with&nbsp;only-K=true&nbsp;to&nbsp;only&nbsp;do&nbsp;this&nbsp;k-point
(define-param&nbsp;k-interp&nbsp;4)&nbsp;&nbsp;&nbsp;;&nbsp;the&nbsp;number&nbsp;of&nbsp;k&nbsp;points&nbsp;to&nbsp;interpolate

(if&nbsp;only-K
&nbsp;&nbsp;&nbsp;&nbsp;(set!&nbsp;k-points&nbsp;(list&nbsp;K))
&nbsp;&nbsp;&nbsp;&nbsp;(set!&nbsp;k-points&nbsp;(interpolate&nbsp;k-interp&nbsp;(list&nbsp;Gamma&nbsp;M&nbsp;K&nbsp;Gamma))))
&nbsp;
(set-param!&nbsp;resolution&nbsp;(vector3&nbsp;32&nbsp;32&nbsp;32))

(set-param!&nbsp;num-bands&nbsp;9)
;&nbsp;Run&nbsp;even&nbsp;and&nbsp;odd&nbsp;bands,&nbsp;outputting&nbsp;fields&nbsp;only&nbsp;at&nbsp;the&nbsp;K&nbsp;point:

(run-zeven&nbsp;(output-at-kpoint&nbsp;K&nbsp;output-hfield-z))

_______________________________________________
mpb-discuss mailing list
[email protected]
http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss
embedded0 (image/png, 15.2 KB) - not displayed