1. Zoran Popović, University of Belgrade, Faculty of Physics, Serbia
2. Ivanka Milošević, Faculty of Physics, University of Belgrade, Serbia
Due to their suitable structure and geometry, modelling of carbon nanotubes is enabled from a single representative atom, by symmetry transformation. Also, symmetry can be used in order to reduce calculation for prediction of electronics as well the wide range of their relevant physical properties. Homogeneous mechanical deformation, that preserved symmetry, caused Hamiltonian reparameterization that influenced band change. For semiconducting carbon nanotubes, the most significant changes occur around Fermi level, where are conducted and valence bands with the same angular quantum number. Could be selected deformation which forces them to come close to each other. Bands approach always in two symmetrical points related to the gamma point for homogeneous deformation. In accordance with the non-crossing rule, they never intersect and become metallic, even in the moment they take cone-like shape when it comes to the change of Berry phase for 2 π. This indicates that the average position of two electrons simultaneously is changed from the middle of the monomer to its ends or vice versa, despite it being semiconductor. Respecting symmetry, two electrons are splitting at the middle of each monomer, tunnelling to the opposite ends (or vice versa) where they are clustering in new states.
Ključne reči :
Tematska oblast:
SIMPOZIJUM A - Nauka materije, kondenzovane materije i fizika čvrstog stanja
Datum:
12.06.2024.
Contemporary Materials 2024 - Savremeni Materijali
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