On Tue, 16 May 2006, hbchen8888 wrote:
The Mpb can not compute DOS(and LDOS) of photonic crystals.
Although MPB does not give you a built-in function to compute the DOS, it
gives you all the information that you need.
In particular, the DOS can be computed directly from the band
diagram...see e.g. the dos.scm example file included with MPB.
You can get a more accurate DOS by using the group velocity; MPB can also
compute the group velocity for you, but you have to implement the formula
to find the DOS yourself. See:
G. Gilat and L. J. Raubenheimer, "Accurate Numerical Method for
Calculating Frequency-Distribution Functions in Solids," Phys. Rev. 144,
p. 390-395 (1966).
This issue has also been discussed in the past on the MPB mailing list.
Could you recommend a software that can compute DOS and LDOS of PCs to me?
As I said, MPB is perfectly fine to get the DOS.
In principle, you can also use MPB to get the LDOS, since the LDOS is
defined by a similar formula to the DOS except that it also includes an
\epsilon |E|^2 term, which you can also get from MPB.
Alternatively, you can compute the LDOS from the diagonal elements of the
Green's function (and the DOS from its trace). This can be computed for
example by our Meep time-domain code (see ab-initio.mit.edu/meep). The
advantage of using a time-domain code is that you can get the LDOS for a
whole spectrum of frequencies at once by Fourier-transforming the response
to a short impulse.
Cordially,
Steven G. Johnson
_______________________________________________
mpb-discuss mailing list
[email protected]
http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss
