1 / 24

Second Harmonic Generation From Surfaces Nicolas Tancogne-Dejean, Valérie Véniard

Second Harmonic Generation From Surfaces Nicolas Tancogne-Dejean, Valérie Véniard. Laboratoire des Solides Irradiés,Ecole Polytechnique, CNRS, CEA/DSM European Theoretical Spectroscopy Facility. Outline. Nonlinear optic and second harmonic generation Surfaces

bruis
Download Presentation

Second Harmonic Generation From Surfaces Nicolas Tancogne-Dejean, Valérie Véniard

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Second Harmonic Generation From SurfacesNicolas Tancogne-Dejean, Valérie Véniard Laboratoire des Solides Irradiés,Ecole Polytechnique, CNRS, CEA/DSM EuropeanTheoreticalSpectroscopyFacility Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  2. Outline Nonlinear optic and second harmonic generation Surfaces How do we get the surface spectrum for SHG Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  3. Response to a perturbation Perturbation Response Polarisation Electric field LinearResponse NonlinearResponse • SumfrequencyGeneration • Absorption • Kerr effect • Refraction • Pockelseffect • Four-wavemixing • … • Birefringence • … Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  4. Second harmonic generation First nonlinear term Centrosymmetricmaterial : First nonlinear term : Non centrosymmetricmaterial : G. Frankel Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  5. Applications of second harmonic generation (SHG) Nanotubes characterization(PRB 77 125428) Biological tissues/neurons imaging (Biophys. J. 81 493; PNAS 103, 786) Nanoparticles imaging and microscopy ( C-L Hsieh PhD thesis, Caltech 2011 ) Thin films and surfaces characterization(PRB 89 075110) Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  6. Outline Nonlinear optic and second harmonic generation Surfaces How do we get the surface spectrum for SHG Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  7. Surfaces Different surfaces for the same material (e.g. Silicon) Si(111) 7x7 Si(001) 2x1 Asymmetric dimers Dangling bonds Si(001) 4x2 Surface = symmetry breaking Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  8. Model of surface – Super-cells Best representation of a surface Plane waves What we want Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  9. Model of surface – Super-cells Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  10. Outline Nonlinear optic and second harmonic generation Surfaces How do we get the surface spectrum for SHG Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  11. Second order response in Time-Dependent DFT Ground state (DFT) - Electronic structure : LDA functional - ABINIT code Second order response Independent Particles Approximation (IPA) Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  12. Extraction of one surface signal Direct Calculation Vacuum Front • Inversion symmetry Surf. C(z) Back Surf. Vacuum [1] L. Reining et al., Phys. Rev. B 50, 8411 (1994) It is possible to extract the signal from only one surface, using a new operator instead of p[1] Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  13. Second-order response z C(z) function ab initio calculation Extracted Signal C(z) Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  14. Extraction from two super-cells z z Signal from clean surface from two different super-cells Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  15. Extraction from two super-cells z z Independence of the two surfaces Signal from dihydride surface from two different super-cells Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  16. Extraction from two super-cells z z Independence of the two surfaces Calculation of the second orderresponsefromonly one surface Signal from dihydride surface from two different super-cells Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  17. Some results for Si(001)2x1 Clean Surface Monohydride Adaptedfrom J. I. Dadap, et al., Phys. Rev. B 56, 13367 (1997) Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  18. Some results for Si(001)2x1 Clean Surface Monohydride Adaptedfrom J. I. Dadap, et al., Phys. Rev. B 56, 13367 (1997) ab initiocalculations 40 Si atoms – 256 k-points Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  19. Conclusion Conclusion Perspective We have presented a scheme for extracting the response from one surface in a super-cell approach Beyond the Independent Particle Approximation - Local-field effects - Many body effects Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  20. Thank you for your attention Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  21. Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  22. Validation of the approach z Comparisonwith exact results for somespecific components of the tensor Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  23. Validation of the approach z Comparisonwith exact results for somespecific components of the tensor Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

  24. Some results for Si(001)2x1 Clean Surface Monohydride Adaptedfrom J. I. Dadap, et al., Phys. Rev. B 56, 13367 (1997) ab initiocalculations 40 Si atoms – 256 k-points Condensed Matter in Paris - CMD 25 JMC 14 - August 2014

More Related