Sum frequency generation - Revision history

Attacc at 07:16, 9 May 2025

2025-05-09T07:16:57Z

← Older revision		Revision as of 07:16, 9 May 2025
Line 8:		Line 8:
	If it is not the case please refer to the previous tutorials: <br>[[Linear response using Dynamical Berry Phase]] and [[Real time approach to non-linear response (SHG)]]		If it is not the case please refer to the previous tutorials: <br>[[Linear response using Dynamical Berry Phase]] and [[Real time approach to non-linear response (SHG)]]
	and Ref.<ref name=nl>[https://arxiv.org/abs/1309.4012 Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second- and third-harmonic generation in semiconductors], C. Attaccalite and M. Grüning, Phys. Rev. B '''88''', 235113(2013)</ref>.<br><br>		and Ref.<ref name=nl>[https://arxiv.org/abs/1309.4012 Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second- and third-harmonic generation in semiconductors], C. Attaccalite and M. Grüning, Phys. Rev. B '''88''', 235113(2013)</ref>.<br><br>
	This tutorial has been made possible thanks to the work of [https://www.uni-giessen.de/de/fbz/fb07/fachgebiete/physik/institute/theorie/agsanna/people/mike-pionteck Mike N. Pionteck] published in Ref. <ref name=sfg>[https://arxiv.org/abs/2503.07095 Sum frequency generation from real-time simulations in two-dimensional crystals], M. N. Pionteck, M. Grüning, S. Sanna, C. Attaccalite</ref>, results are also presented in this Libreoffice presentation~~<ref>~~[https://www.attaccalite.com/wp-content/uploads/2025/04/sum_frequency.odp sum_frequency.odp]~~</ref>~~ .<br>		This tutorial has been made possible thanks to the work of [https://www.uni-giessen.de/de/fbz/fb07/fachgebiete/physik/institute/theorie/agsanna/people/mike-pionteck Mike N. Pionteck] published in Ref. <ref name=sfg>[https://arxiv.org/abs/2503.07095 Sum frequency generation from real-time simulations in two-dimensional crystals], M. N. Pionteck, M. Grüning, S. Sanna, C. Attaccalite</ref>, results are also presented in this Libreoffice presentation [https://www.attaccalite.com/wp-content/uploads/2025/04/sum_frequency.odp sum_frequency.odp].<br>

	== DFT calculations ==		== DFT calculations ==

Attacc at 07:16, 9 May 2025

2025-05-09T07:16:31Z

← Older revision		Revision as of 07:16, 9 May 2025
Line 8:		Line 8:
	If it is not the case please refer to the previous tutorials: <br>[[Linear response using Dynamical Berry Phase]] and [[Real time approach to non-linear response (SHG)]]		If it is not the case please refer to the previous tutorials: <br>[[Linear response using Dynamical Berry Phase]] and [[Real time approach to non-linear response (SHG)]]
	and Ref.<ref name=nl>[https://arxiv.org/abs/1309.4012 Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second- and third-harmonic generation in semiconductors], C. Attaccalite and M. Grüning, Phys. Rev. B '''88''', 235113(2013)</ref>.<br><br>		and Ref.<ref name=nl>[https://arxiv.org/abs/1309.4012 Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second- and third-harmonic generation in semiconductors], C. Attaccalite and M. Grüning, Phys. Rev. B '''88''', 235113(2013)</ref>.<br><br>
	This tutorial has been made possible thanks to the work of [https://www.uni-giessen.de/de/fbz/fb07/fachgebiete/physik/institute/theorie/agsanna/people/mike-pionteck Mike N. Pionteck] published in Ref. <ref name=sfg>[https://arxiv.org/abs/2503.07095 Sum frequency generation from real-time simulations in two-dimensional crystals], M. N. Pionteck, M. Grüning, S. Sanna, C. Attaccalite</ref>, results are also presented in this Libreoffice presentation<ref>[https://www.attaccalite.com/wp-content/uploads/2025/04/sum_frequency.odp sum_frequency.odp]</re> .<br>		This tutorial has been made possible thanks to the work of [https://www.uni-giessen.de/de/fbz/fb07/fachgebiete/physik/institute/theorie/agsanna/people/mike-pionteck Mike N. Pionteck] published in Ref. <ref name=sfg>[https://arxiv.org/abs/2503.07095 Sum frequency generation from real-time simulations in two-dimensional crystals], M. N. Pionteck, M. Grüning, S. Sanna, C. Attaccalite</ref>, results are also presented in this Libreoffice presentation<ref>[https://www.attaccalite.com/wp-content/uploads/2025/04/sum_frequency.odp sum_frequency.odp]</ref> .<br>

	== DFT calculations ==		== DFT calculations ==

Attacc at 07:16, 9 May 2025

2025-05-09T07:16:13Z

← Older revision		Revision as of 07:16, 9 May 2025
Line 8:		Line 8:
	If it is not the case please refer to the previous tutorials: <br>[[Linear response using Dynamical Berry Phase]] and [[Real time approach to non-linear response (SHG)]]		If it is not the case please refer to the previous tutorials: <br>[[Linear response using Dynamical Berry Phase]] and [[Real time approach to non-linear response (SHG)]]
	and Ref.<ref name=nl>[https://arxiv.org/abs/1309.4012 Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second- and third-harmonic generation in semiconductors], C. Attaccalite and M. Grüning, Phys. Rev. B '''88''', 235113(2013)</ref>.<br><br>		and Ref.<ref name=nl>[https://arxiv.org/abs/1309.4012 Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second- and third-harmonic generation in semiconductors], C. Attaccalite and M. Grüning, Phys. Rev. B '''88''', 235113(2013)</ref>.<br><br>
	This tutorial has been made possible thanks to the work of [https://www.uni-giessen.de/de/fbz/fb07/fachgebiete/physik/institute/theorie/agsanna/people/mike-pionteck Mike N. Pionteck] published in Ref. <ref name=sfg>[https://arxiv.org/abs/2503.07095 Sum frequency generation from real-time simulations in two-dimensional crystals], M. N. Pionteck, M. Grüning, S. Sanna, C. Attaccalite</ref> .<br>		This tutorial has been made possible thanks to the work of [https://www.uni-giessen.de/de/fbz/fb07/fachgebiete/physik/institute/theorie/agsanna/people/mike-pionteck Mike N. Pionteck] published in Ref. <ref name=sfg>[https://arxiv.org/abs/2503.07095 Sum frequency generation from real-time simulations in two-dimensional crystals], M. N. Pionteck, M. Grüning, S. Sanna, C. Attaccalite</ref>, results are also presented in this Libreoffice presentation<ref>[https://www.attaccalite.com/wp-content/uploads/2025/04/sum_frequency.odp sum_frequency.odp]</re> .<br>

	== DFT calculations ==		== DFT calculations ==

Attacc: /* Analysis of all runs */

2025-03-11T08:36:28Z

Analysis of all runs

← Older revision		Revision as of 08:36, 11 March 2025
Line 155:		Line 155:

	You can compare these results with those of Ref.<ref name=sfg></ref>. Note that in order to get fully converged results, you need to increase: the number of k-points, the length of the simulations, and the number of frequencies used in the plots. Converged parameters for this system can be found in Ref.<ref name=sfg></ref>, including all details to include excitonic effects.<br>		You can compare these results with those of Ref.<ref name=sfg></ref>. Note that in order to get fully converged results, you need to increase: the number of k-points, the length of the simulations, and the number of frequencies used in the plots. Converged parameters for this system can be found in Ref.<ref name=sfg></ref>, including all details to include excitonic effects.<br>
	'''Important''': In case of degenerate or multiple frequencies <math>\omega_1 = n \omega_2></math> where n is an integer, the algorithm used to extract the SFG/DFG coefficient could not converge. In this case you can discard these points and use the neighbour solution for interpolation, see discussion in reference <ref name=sfg></ref>. Another possibility is to use a least-squares fit algohrithm that starts from the neighbour solution to find the SFG/DFG coefficents, this is implemented in YamboPy in the sum_frequency.py file, but is commented.		'''Important''': In case of degenerate or multiple frequencies <math>\omega_1 = n \omega_2</math> where <math>n</math> is an integer, the algorithm used to extract the SFG/DFG coefficient could not converge. In this case you can discard these points and use the neighbour solution for interpolation, see discussion in reference <ref name=sfg></ref>. Another possibility is to use a least-squares fit algohrithm that starts from the neighbour solution to find the SFG/DFG coefficents, this is implemented in YamboPy in the sum_frequency.py file, but is commented.

	== Comparison with SHG ==		== Comparison with SHG ==

Attacc: /* Analysis of all runs */

2025-03-11T08:36:03Z

Analysis of all runs

← Older revision		Revision as of 08:36, 11 March 2025
Line 155:		Line 155:

	You can compare these results with those of Ref.<ref name=sfg></ref>. Note that in order to get fully converged results, you need to increase: the number of k-points, the length of the simulations, and the number of frequencies used in the plots. Converged parameters for this system can be found in Ref.<ref name=sfg></ref>, including all details to include excitonic effects.<br>		You can compare these results with those of Ref.<ref name=sfg></ref>. Note that in order to get fully converged results, you need to increase: the number of k-points, the length of the simulations, and the number of frequencies used in the plots. Converged parameters for this system can be found in Ref.<ref name=sfg></ref>, including all details to include excitonic effects.<br>
	'''Important''': In case of degenerate or multiple frequencies $$\omega_1 = n \omega_2$$ where n is an integer, the algorithm used to extract the SFG/DFG coefficient could not converge. In this case you can discard these points and use the neighbour solution for interpolation, see discussion in reference <ref name=sfg></ref>. Another possibility is to use a least-squares fit algohrithm that starts from the neighbour solution to find the SFG/DFG coefficents, this is implemented in YamboPy in the sum_frequency.py file, but is commented.		'''Important''': In case of degenerate or multiple frequencies <math>\omega_1 = n \omega_2></math> where n is an integer, the algorithm used to extract the SFG/DFG coefficient could not converge. In this case you can discard these points and use the neighbour solution for interpolation, see discussion in reference <ref name=sfg></ref>. Another possibility is to use a least-squares fit algohrithm that starts from the neighbour solution to find the SFG/DFG coefficents, this is implemented in YamboPy in the sum_frequency.py file, but is commented.

	== Comparison with SHG ==		== Comparison with SHG ==

Attacc: /* Analysis of all runs */

2025-03-11T08:35:37Z

Analysis of all runs

← Older revision		Revision as of 08:35, 11 March 2025
Line 155:		Line 155:

	You can compare these results with those of Ref.<ref name=sfg></ref>. Note that in order to get fully converged results, you need to increase: the number of k-points, the length of the simulations, and the number of frequencies used in the plots. Converged parameters for this system can be found in Ref.<ref name=sfg></ref>, including all details to include excitonic effects.<br>		You can compare these results with those of Ref.<ref name=sfg></ref>. Note that in order to get fully converged results, you need to increase: the number of k-points, the length of the simulations, and the number of frequencies used in the plots. Converged parameters for this system can be found in Ref.<ref name=sfg></ref>, including all details to include excitonic effects.<br>
	'''Important''': In case of degenerate or multiple frequencies $\omega_1 = n \omega_2$ where n is an integer, the algorithm used to extract the SFG/DFG coefficient could not converge. In this case you can discard these points and use the neighbour solution for interpolation, see discussion in reference <ref name=sfg></ref>. Another possibility is to use a least-squares fit algohrithm that starts from the neighbour solution to find the SFG/DFG coefficents, this is implemented in YamboPy in the sum_frequency.py file, but is commented.		'''Important''': In case of degenerate or multiple frequencies $$\omega_1 = n \omega_2$$ where n is an integer, the algorithm used to extract the SFG/DFG coefficient could not converge. In this case you can discard these points and use the neighbour solution for interpolation, see discussion in reference <ref name=sfg></ref>. Another possibility is to use a least-squares fit algohrithm that starts from the neighbour solution to find the SFG/DFG coefficents, this is implemented in YamboPy in the sum_frequency.py file, but is commented.

	== Comparison with SHG ==		== Comparison with SHG ==

Attacc: /* Analysis of all runs */

2025-03-11T08:35:17Z

Analysis of all runs

← Older revision		Revision as of 08:35, 11 March 2025
Line 154:		Line 154:
	[[File:SFG 2D.png\|center \| 500px\|SFG in 2D]]		[[File:SFG 2D.png\|center \| 500px\|SFG in 2D]]

	You can compare these results with ~~the one~~ of Ref.<ref name=sfg></ref>. ~~Notice~~ that in order to ~~have full~~ converged results you ~~have~~ to increase: the number of k-points, length of the simulations and the number of ~~frequency~~ used in the plots. Converged parameters for this system can be found in Ref.<ref name=sfg></ref>, including ~~also~~ all details to include excitonic effects.		You can compare these results with those of Ref.<ref name=sfg></ref>. Note that in order to get fully converged results, you need to increase: the number of k-points, the length of the simulations, and the number of frequencies used in the plots. Converged parameters for this system can be found in Ref.<ref name=sfg></ref>, including all details to include excitonic effects.<br>
			'''Important''': In case of degenerate or multiple frequencies $\omega_1 = n \omega_2$ where n is an integer, the algorithm used to extract the SFG/DFG coefficient could not converge. In this case you can discard these points and use the neighbour solution for interpolation, see discussion in reference <ref name=sfg></ref>. Another possibility is to use a least-squares fit algohrithm that starts from the neighbour solution to find the SFG/DFG coefficents, this is implemented in YamboPy in the sum_frequency.py file, but is commented.

	== Comparison with SHG ==		== Comparison with SHG ==

Attacc: /* Analysis of all runs */

2025-03-11T08:31:52Z

Analysis of all runs

← Older revision		Revision as of 08:31, 11 March 2025
Line 153:		Line 153:

	[[File:SFG 2D.png\|center \| 500px\|SFG in 2D]]		[[File:SFG 2D.png\|center \| 500px\|SFG in 2D]]

			You can compare these results with the one of Ref.<ref name=sfg></ref>. Notice that in order to have full converged results you have to increase: the number of k-points, length of the simulations and the number of frequency used in the plots. Converged parameters for this system can be found in Ref.<ref name=sfg></ref>, including also all details to include excitonic effects.

	== Comparison with SHG ==		== Comparison with SHG ==

Attacc at 08:10, 11 March 2025

2025-03-11T08:10:16Z

← Older revision		Revision as of 08:10, 11 March 2025
Line 8:		Line 8:
	If it is not the case please refer to the previous tutorials: <br>[[Linear response using Dynamical Berry Phase]] and [[Real time approach to non-linear response (SHG)]]		If it is not the case please refer to the previous tutorials: <br>[[Linear response using Dynamical Berry Phase]] and [[Real time approach to non-linear response (SHG)]]
	and Ref.<ref name=nl>[https://arxiv.org/abs/1309.4012 Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second- and third-harmonic generation in semiconductors], C. Attaccalite and M. Grüning, Phys. Rev. B '''88''', 235113(2013)</ref>.<br><br>		and Ref.<ref name=nl>[https://arxiv.org/abs/1309.4012 Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second- and third-harmonic generation in semiconductors], C. Attaccalite and M. Grüning, Phys. Rev. B '''88''', 235113(2013)</ref>.<br><br>
	This tutorial has been made possible thanks to the work of [https://www.uni-giessen.de/de/fbz/fb07/fachgebiete/physik/institute/theorie/agsanna/people/mike-pionteck Mike N. Pionteck] published in Ref. <ref name=sfg>[~~http~~://arxiv.org Sum frequency generation from real-time simulations in two-dimensional crystals], M. N. Pionteck, M. Grüning, S. Sanna, C. Attaccalite</ref> .<br>		This tutorial has been made possible thanks to the work of [https://www.uni-giessen.de/de/fbz/fb07/fachgebiete/physik/institute/theorie/agsanna/people/mike-pionteck Mike N. Pionteck] published in Ref. <ref name=sfg>[https://arxiv.org/abs/2503.07095 Sum frequency generation from real-time simulations in two-dimensional crystals], M. N. Pionteck, M. Grüning, S. Sanna, C. Attaccalite</ref> .<br>

	== DFT calculations ==		== DFT calculations ==

Attacc: /* Checking the Fourier analysis */

2025-03-10T15:35:26Z

Checking the Fourier analysis

← Older revision		Revision as of 15:35, 10 March 2025
Line 125:		Line 125:
	=== Checking the Fourier analysis===		=== Checking the Fourier analysis===
	In the previous script we turned on the flag <code>prn_Peff=True</code> that automatically will produce a series of file to check if the Fourier was successful.		In the previous script we turned on the flag <code>prn_Peff=True</code> that automatically will produce a series of file to check if the Fourier was successful.
	The files <code> o.YamboPy-~~sampling_FX~~</code> contain the sampling points used to fix the real-time polarization, you can for example plot <code>o.YamboPy-sampling_F1</code> vs <code>o~~-TEST~~.polarization_F1</code> together to see which part of <math>P(t)</math> is used to extract the response functions:		The files <code> o.YamboPy-sampling_F1</code> contain the sampling points used to fix the real-time polarization, you can for example plot <code>o.YamboPy-sampling_F1</code> vs <code>o.polarization_F1</code> together to see which part of <math>P(t)</math> is used to extract the response functions:
	[[File:Sampling vs p.png\|center\| 700px \|sampling_p]]		[[File:Sampling vs p.png\|center\| 700px \|sampling_p]]

	Then you can check if real-time polarization is well reconstructed by the Fourier coefficients calculated by the script by plotting <code> o.YamboPy-pol_reconstructed_F1</code> vs <code>o~~-TEST~~.polarization_F1</code>		Then you can check if real-time polarization is well reconstructed by the Fourier coefficients calculated by the script by plotting <code> o.YamboPy-pol_reconstructed_F1</code> vs <code>o.polarization_F1</code>

	[[File:Reconstructed p vs p.png\|center \|700px \|Reconstructed polarization]]		[[File:Reconstructed p vs p.png\|center \|700px \|Reconstructed polarization]]