scholarly journals Relativistic tight-binding approximation method for materials immersed in the magnetic field

2013 ◽  
Vol 38 (4) ◽  
pp. 663-665
Author(s):  
Katsuhiko Higuchi ◽  
Dipendra Bahadur Hamal ◽  
Kei Yamamoto ◽  
Masahiko Higuchi
2010 ◽  
Vol 24 (09) ◽  
pp. 849-857 ◽  
Author(s):  
MEI HAN ◽  
YONG ZHANG

The quantum conductance of the electron interferometers composed of the armchair and metallic zigzag single-walled carbon nanotubes (SWNTs) in an axial magnetic field lower than 100 T has been studied by using the tight-binding approximation and Landauer–Buttiker formula. Quantum conductance oscillation as a function of gate voltage due to Fabry–Perot like electron interference was found. The analytical expressions of the rapid and slow conductance oscillation periods for the armchair SWNTs have been derived. It is shown that they depend on the magnetic field, gate voltage, and tube length. For the case of the metallic zigzag SWNTs, except rapid conductance oscillation, slow conductance oscillation was also found, which should not exist without the axial magnetic field.


2020 ◽  
Vol 75 (11) ◽  
pp. 987-998
Author(s):  
Danica Krstovska ◽  
Aleksandar Skeparovski

AbstractWe have calculated and analyzed the surface-state energies and wave functions in quasi-two dimensional (Q2D) organic conductors in a magnetic field parallel to the surface. Two different forms for the electron energy spectrum are used in order to obtain more information on the elementary properties of surface states in these conductors. In addition, two mathematical approaches are implemented that include the eigenvalue and eigenstate problem as well as the quantization rule. We find significant differences in calculations of the surface-state energies arising from the specific form of the energy dispersion law. This is correlated with the different conditions needed to calculate the surface-state energies, magnetic field resonant values and the surface wave functions. The calculations reveal that the value of the coordinate of the electron orbit must be different for each state in order to numerically calculate the surface energies for one energy dispersion law, but it has the same value for each state for the other energy dispersion law. This allows to determine more accurately the geometric characteristics of the electron skipping trajectories in Q2D organic conductors. The possible reasons for differences associated with implementation of two distinct energy spectra are discussed. By comparing and analyzing the results we find that, when the energy dispersion law obtained within the tight-binding approximation is used the results are more relevant and reflect the Q2D nature of the organic conductors. This might be very important for studying the unique properties of these conductors and their wider application in organic electronics.


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