Simetrija diperiodicnih sistema


Simetrije diperiodicnih sistema su opisane diperiodicnim grupama. Odredjene su njihove ireducibilne reprezentacije, sto je osnov za simetrijsku analizu fizickih svojstava sistema periodicnih u dva pravca.
 
 
YBa2Cu3O7 (123) Jahn-Teller-ov teorem NARUSEN kod samo nekoliko struktura. 
Medju njima CuO2 provodna ravan HTS jedinjenja. 
Teorem narusavaju upravo 
elektronska stanja koja dozvoljavaju d(x2-y2) sparivanje.
Brillouinova zona CuO2

U toku je rad na kompjuterskoj implementaciji diperiodicne simetrije (program za ireducibilne reprezentacije je zavrsen i moze se dobiti).



Reference:
I. Milosevic, M. Krcmar, B. Nikolic and M. Damnjanovic,
Vibronic (In)Stability for Mono- and Di- periodic Systems,
VI International Conference on "Mathematical Results in Quantum Mechanics",
Ascona, Switzerland, (1996) 26.
I. Milosevic, M. Krcmar, B. Nikolic and M. Damnjanovic ,
The Breakdown of the Jahn-Teller Theorem in CuO2Layers,
in Proceedings of the XXI International Colloquium on Group Theoretical
Methods in Physics: Physical Applications and Mathematical Aspects of
Geometry, Groups and Algebras, eds. H.-D. Doebner, W. Scherer and C. Schulte,
Vol. II, pg. 810-4, World Scientific, Singapore, 1997.
I. Milosevic, B. Nikolic, M. Damnjanovic and M. Krcmar,
Irreducible Representations of Diperiodic Groups
J. Phys. A: Math. Gen. 31 (1998) 3652-48.

          B. Nikolic, M. Damnjanovic and I. Milosevic,
          Electron-phonon Coupling Reduction in Tetragonal and Hexagonal Layers,
          2D Conductivity in Surface States and Monolayers, 5-8 March 2001, Bad Honnef, Germany