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D02L01 M Damnjanovic

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D02L01 M Damnjanovic

  1. 1. FACULTY OF PHYSICS ФАКУЛТЕТ University of Belgrade www.ff.bg.ac.rs
  2. 2. BASICS
  3. 3. STUFF 73 professors and assistants 2 institutes: of physics of meteorology 3 building in the central area of Belgrade 9000 m 2 14 Labs 150 batchelor ( )+ 20 master + 30 Ph.D. students yearly; ~100 0 enrolled altogether
  4. 4. PROGRAMS <ul><li>4 batchelor (4 years) +master (1 year) </li></ul><ul><li>Theoretical and experimental physics </li></ul><ul><li>Applied and computational physics </li></ul><ul><li>Educational Physics </li></ul><ul><li>Meteorology </li></ul><ul><li>3 Ph. D. : </li></ul><ul><li>Physics, </li></ul><ul><li>Meteorology, </li></ul><ul><li>Biophysics </li></ul><ul><li>1 specialistic </li></ul><ul><li>Medical physics </li></ul>
  5. 5. EDUCATIONAL ACTIVITIES <ul><li>Laboratory for design and development of teaching aids prototypes: ~30 types of equipments </li></ul>~100 textbooks ~ 150 courses (also for foreign students) Seminars for grammar school pupils and teachers
  6. 6. RESEARCH
  7. 7. BASIC RESEARCH 9 Projects of Serbian Ministry of Science <ul><li>Nanoscience, Material science, Condensed matter: </li></ul><ul><li>4 projects (35 people) </li></ul><ul><li>Lasers, Plasma, Ionized gasses: </li></ul><ul><li>4 projects (30 people) </li></ul><ul><li>Meteorology </li></ul><ul><li>1 project (10 people) </li></ul>
  8. 8. APPLIED RESEARCH <ul><li>PYROMETRY </li></ul><ul><li>7 people, 3 projects, 3 patents </li></ul><ul><li>ECOLOGY </li></ul><ul><li>5 people,1 project, 2 patents </li></ul>
  9. 9. CENTRES OF EXCELLENCE
  10. 10. CENTRES OF EXCELLENCE <ul><li>NanoLab: Nanoscience </li></ul><ul><li>12 people, Theory+Experiment </li></ul><ul><li>Equipment: </li></ul><ul><li>AF/ST Microscopy </li></ul><ul><li>Small computing cluster </li></ul><ul><li>Spectrofluorimeter </li></ul>
  11. 11. CENTRES OF EXCELLENCE <ul><li>NanoLab: Nanoscience </li></ul><ul><li>12 people, Theory+Experiment </li></ul><ul><li>Equipment: </li></ul><ul><li>AF/ST Microscopy </li></ul><ul><li>Small computing cluster </li></ul><ul><li>Spectrofluorimeter </li></ul><ul><li>SYNGLab: synthesis of nanostructures </li></ul><ul><li>in gass discharges </li></ul><ul><li>3 researchers, Experiment </li></ul><ul><li>Equipment: vacuum systems, CCD cameras </li></ul>
  12. 12. NETWORKING <ul><li>NanoLab: </li></ul><ul><ul><li>NanoLabFor: FP6 project (2006-2009, M. Damnjanovic ) </li></ul></ul><ul><ul><li>Synthesis/properties of carbon nanostructures: </li></ul></ul><ul><li>Scopes (Swiss project with Swiss, Hungarian and </li></ul><ul><li>Armeninan groups, 2010-1012, I. Milosevic ) </li></ul><ul><ul><li>5 bilateral projects from 2003 (Slovenia, </li></ul></ul><ul><ul><li>Germany, France, Greece) </li></ul></ul><ul><li>SYNGLab: </li></ul><ul><ul><li>GLADNET: FP6 project (Maria Curie Ph. D. training, 12 members Network, N. Konjevic ) </li></ul></ul>
  13. 13. www.nanolab.rs NanoLab Theory: Symmetry: Line Groups; Computing: POLSym (DFT, TBA) Systems: Nano- tubes, rods, wires, springs Experimental: nanotemplates, pyrometry
  14. 14. OUTLINE <ul><li>Belgrade S chool of Q uantum & M athematical P h y sics </li></ul><ul><li>NanoLab </li></ul><ul><li>Line groups, general applications & exploiting their symmetry </li></ul><ul><li>SWCNTs: structure = symmetry ( El. Bands, Optical spectra, Phonon dispersions, Raman scattering, Stone-Wales deformation & pentaheptite NTs) </li></ul><ul><li>DWCNTs: interaction = symmetry breaking ( Rigid layer modes, Super slippery modes &Telescope effect) </li></ul>
  15. 15. Belgrade S chool of Q uantum & M athematical P h y sics <ul><li>Chair of quantum and mathematical physics </li></ul><ul><li>F. Herbut , M. Vuji čić </li></ul><ul><li>Božović , Đ . Šijački , I . Ivanović </li></ul><ul><li>M. Damnjanović </li></ul><ul><li>I . Milošević </li></ul><ul><li>Т. Vuković , B . Nikolić , D. Stojković </li></ul><ul><li>E. D о b а rdžić , S . Dmitrović , V. Stevanović , </li></ul><ul><li>B . Dakić , Z. Popović , B. Vi šić </li></ul>NanoLab 2000
  16. 16. NanoLab Z. Popović B. Dakić I . Milošević E. Dobardžić Т. Vuković S. Dmitrović B. Nikolić M. Damnjanovic
  17. 17. Line Groups March 2010 (to appear)
  18. 18. Regular quasi-1D Systems DNA model ZnO nanospring SWCNT
  19. 19. Line groups PRB 25 (1982) 6987 Incommensurate and chiral groups are from the families 1 & 5 ZP=PZ arrangement and monomer symmetry are compatible L=Z P 13 infinite families
  20. 20. LG symmetric E(3) orbits PRB 47 (1993) 7805, Polymer 38 (1997) 4445, PRB 76 (2007) 0354391 15 classes: elementary monoperiodic systems
  21. 21. Diffraction patterns PRB 76 (2007) 0354391, pss (b) 246 (2009) 2631,
  22. 22. BANDS+ASSIGNATION PRB 65 (2002) 045418; JPA 36 (2003) 5707 ENERGIES: bands over BZ, assigned by m and Π. Time reversal: IBZ=[0, π ]. STATES: Symmetry adapted = generalized Bloch
  23. 23. CONSERVATION LAWS = SELECTION RULES <ul><li>k f m f Π f | A kmΠ | k i m i Π i  ≠ 0 if </li></ul><ul><li>k f - k i = k & m f - m i = m & Π f Π i Π ≠ -1 </li></ul>PRB 65 (2002) 045418 More details: Clebsch-Gordan coefficients ∙ ∙
  24. 24. Nanotubes: layer rolling PRB 75 (2007) 033404 For each diperiodic group (layer) and each chiral vector line group symmetry of the obtained nanotube is determined SWCNT 5 Chiral 80 13 Achiral 80
  25. 25. SSC 121 (2002) 471; PRB 68 (2003) 045408; 72 (2005) 085426; JPC 16 (2004) L505 (9,0) 285 cm -1 Radial Breathing Mode (8,2) 310 cm -1 (6,6) 275 cm -1 Nonradial components: z RBM ( D, θ )=(0.197 D -1 -0.167 D -3 )cos(3 θ ) ω [cm -1 ] = 2243/D [Ǻ] D characterized by Raman 0 A 0 +
  26. 26. OPTICAL CONDUCTIVITY PRB 62 (2000) 6971; 67 (2003) 165418; 69} (2004) 113408 Selection rules: ∆k=0, ∆m=0, σ v : Π f Π i ≠ -1, σ h , σ U : Π f Π i ≠ 1 Parallel polarization Identified zeolite grown tubes Dipole approximation Different selection rules for ∟ field = Dichroism
  27. 27. Plasmons RPA calculated dielectric function (transfer q < 1 Ǻ -1 ) Fit: q < 0.5 Ǻ -1 E p ~ q, q > 0.5 Ǻ -1 E p ~ q 2 PRB 77 (2008) 245415 Armchair: strong π plasmon peak (dispersion in q ) Semiconducting: π plasmon+ nondispersive optical
  28. 28. Pentaheptite SWCNTs Stone-Wales defect (bond rotation) 2(5+7) 57-tilings  57-CNTs 57CNTs mostly conductive while 6CNTs mostly semiconductive Electro-mechanical nanoswitch Mechanical stretching facilitates 57-transition PRB 76 (2007) 233414
  29. 29. [email_address] Δ D =(6.88±0.40) Å
  30. 30. Rigid layer modes EPJB 34 (2003) 409; NJP 5 (2003) 148; PRB 69 (2004) 153401 LRL(9,0)@(18,0) 0 A 0 - 36 cm -1 TWRL (5,5)@(10,10) 0 B 0 - 46 cm -1
  31. 31. Symmetry & interaction <ul><li>Sum over atoms of walls = groups L W and L W’ ! </li></ul>EPJB 25 (2002) 131 V W’ ( r ) = Σ l’ v ( r , r l’ ) : L W’ -invariant W’ receives L W’ harmonics only Harmonics: H M ω (φ,z) = cos (Mφ + 2πωz) L W    L W’ / L W  L W’ W-W’ interaction V ( Φ,Z ) = Σ ll’ v ( r l , r l’ ) l,l’ over atoms V W ( r ) = Σ l v ( r l , r ) : L W - invariant W emits L W -harmonics only Interaction mediated through common harmonics
  32. 32. W-W’ INTERACTION EPJB 34 (2003) 409; NJP 5 (2003) 148; PRB 69 (2004) 153401 Incommensurate walls: super-slippery Z-sliding: Goldstone Resonance: W-ring of integer W-W’ periods v m = v ∞ Low rotational corrugation
  33. 33. CONCLUSIONS <ul><li>Theory: Line groups, Quasi1D, Diffraction… </li></ul><ul><li>Tools: Symmetry, DFT, POLSym code </li></ul><ul><li>Carbon Nanotubes: </li></ul><ul><ul><li>Line group symmetry, single atom in symcell, </li></ul></ul><ul><ul><li>most of the properties determined by symmetry: Conductivity, Optical activity, Plasmons, Raman spectra, Phonons, Plasmons… </li></ul></ul><ul><ul><li>DWNT: almost frictionless degrees of freedom </li></ul></ul><ul><li>Other quasi1D nanostructures (MS2, ZnO,…) </li></ul><ul><li>Layers (graphene, MS2,…) </li></ul>

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