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### Absorption with light polarized in an arbitrary direction

Posted: Tue Jun 18, 2019 10:40 am
Dear Yambo developers and users:
I want to know if yambo can calculate the light absorbance of a 2D material when the light propagates in an arbitrary direction, i.e. neither parallel nor perpendicular to the surface of the 2D material?

We know that by adjusting the BLongDir parameter, the dielectric function, epsilon_xx (1 0 0), epsilon_yy (0 1 0), epsilon_zz ( 0 0 1), can be obtained.
% BLongDir
1.000000 | 0.000000 | 0.000000 | # [BSS] [cc] Electric Field
%
if BLongDir is set as follows:
% BLongDir
1.000000 | 0.000000 | 1.000000 | # [BSS] [cc] Electric Field
%
then the obtained result is epsilon_xx+epsilon_yy, or other epsilon that discribe the absorption with light propagates in the xz plane with an angle of pi/4 ?

Thanks a lot

Nannan Luo

### Re: Absorption with light polarized in an arbitrary directio

Posted: Wed Jun 19, 2019 10:23 am
Dear Nannan Luo,
or other epsilon that discribe the absorption with light propagates in the xz plane with an angle of pi/4 ?
Yes, the BLongDir is a versor of module 1, then it is multiplicated for the small q0.

Code: Select all

``````% BLongDir
1.000000 | 0.000000 | 1.000000 | # [BSS] [cc] Electric Field
%``````
is a vector 1/sqrt(2)[1,0,1]

Best,
Daniele