using GW in the molecular nano-junctions

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using GW in the molecular nano-junctions

Postby haksu » Tue Oct 27, 2015 8:47 pm

Dear developer

I have finally installed yambo-code afre disaster weeks due to incompetent NetCDF with togather HDF5 program.
I have used NetCDF version 3.6.3 and it works all perfect.
My question is: is there any way to use yambo code i.e. GW approximations molecular nano-junctions?
We are inverstigating nanoparticle structure, not bulk or not only complete metal surface. Like, metal molecule (quantum dot) metal.

Second question is: Can I investigate the plasmon (photon)-exciton interactions using yambo. I did not see in the features of yambo code but since I am new user I want to hear from you.

Thank you

Aksu
University of Bilecik
Department of Physics
Turkey
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Re: using GW in the molecular nano-junctions

Postby Daniele Varsano » Tue Oct 27, 2015 9:15 pm

Dear Aksu,

First question: Yambo can handle bulk (3D), surfaces (2D), wires (1D) and molecules/clusters (0D) systems. When treating non 3D systems using cutoff coulomb techniques is recommended, see e.g.:

Code: Select all
An exact Coulomb cutoff technique for supercell calculations.
C. A. Rozzi, D. Varsano, A. Marini, E. K. U. Gross, and A. Rubio,
Phys. Rev. B 73, 205119 (2006).


Anyway depending on the size of your system, the calculations can be very heavies and you could need large computational resources.

Second question: plasmon-exciton interactions. It is not very clear what do you mean exactly. Yambo can calculate EELS spectra (plasmon) and absorption spectra taking into account excitonic effects. For exciton-plasmon states you can have a look to this paper:

Code: Select all
Exciton-plasmon states in nanoscale materials: breakdown of the Tamm-Dancoff approximation
M. Grüning, A. Marini and X. Gonze
Nano Letters, 9, 2820 (2009)


but I do not know if it is pertinent whit what you are asking.

Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
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Re: using GW in the molecular nano-junctions

Postby haksu » Tue Oct 27, 2015 9:37 pm

Thanks Daniele
You are so quick, thats nice

We are using Non-crossing approximation (NCA) based on the slave-boson transformations for moleculer Hamiltonian in the metal-molecule-metal system.
And non equilibrium Greens function method..anyway in our study we investigate plasmon (induced by laser) and excitonic system. But we have ignored the interaction between the
plasmon (photon) and molecule. Plasmon was taken into account only in the metal surface. I mean, laser pulse make possible to create plasmon on the metal and this plasmon and exciton interaction formulae obtained usin NCA...bla bla bla I thing there is no need so much detail :D . But there is another let say interaction between the photon ( emission after annihilation of the plasmon on the metal surface ) itself and exciton.

I had the second article that you proposed to read with me, but I did not have time to read it. I will.
ıf it is possible this issiue with yambo code then next is preparing the input file :S

Thanks
Aksu
haksu
 
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Re: using GW in the molecular nano-junctions

Postby Daniele Varsano » Tue Oct 27, 2015 9:51 pm

Dear Aksu,
what essentially you can calculate with yambo is quasi particle energies within GW approximation for he self energy and absorption spectra solving the Bethe Salpeter equation. May be you can extract from first principle some quantities useful for your model.

Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
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Re: using GW in the molecular nano-junctions

Postby haksu » Tue Oct 27, 2015 10:00 pm

Dear Daniele

I have to look it yambo code and try to get use to it. Let see what comes
Thanks for advices

Best
Aksu
haksu
 
Posts: 5
Joined: Tue Oct 20, 2015 12:26 pm
Location: Turkey

Re: using GW in the molecular nano-junctions

Postby haksu » Tue Nov 10, 2015 9:44 pm

Hello again dear developers
can we investigate kondo peak using the GW or G0W0 methods with yambo.
For example what I want to do it is .

let say there is a one quantum dot (possible H atom-single energry level) between to nanoparticle (metal or lead). What I want to see is after calculating the GW probably I need
ImG(retarded) (w) in the vertical axis and w-E(fermi) on the horizantal axis. Since I am new I could not do and figure out yet how to do so I need you help.

if I can do that then I want to investigate serial 2 Hyrogen atom as two quantum dots and as paralel (with paralel version it is like real Hyrogen molecule: it has one ground state and one excited state). And I want to see sharp peak which is proof that there is exist Kondo rezonance.

Since GW tutorial is with another example H2 molekül in the another tutorial it might be difficult for me as beginner.
Thanks

Best Aksu
haksu
 
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Re: using GW in the molecular nano-junctions

Postby Daniele Varsano » Sat Nov 14, 2015 3:58 pm

Dear Aksu,
please fill your signature with your affiliation when posting: this is a rule of the forum.
I'm afraid that at the moment it is not possible:
According to this [url=http://nano-bio.ehu.es/files/Non-equilibrium-GW-Thygesen.pdf[]work[/url] it is needed to go beyond the G0W0 approximations.
Even if such implementation is present in yambo, it is still an experimental feature and it is not released as GPL.
Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
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Re: using GW in the molecular nano-junctions

Postby haksu » Mon Nov 16, 2015 4:01 pm

Thanks Danielle
So nothing to do

I will search about it
see you

Best
Aksu
Bilecik University
Department of Physics
Turkey
haksu
 
Posts: 5
Joined: Tue Oct 20, 2015 12:26 pm
Location: Turkey


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