Synopsys: nanotube(n,L)
nanotube is the NanoTCAD ViDES class for the (n,0) zig-zag nanotubes. As inputs, it requires the chirality of the nanotube n and the length of the nanotube L expressed in nanometers.
The attributes of the classes are the following:
- Nc : (int) the number of rings along the nanotube
- n : (int) the number of atoms along each ring
- Eupper : (double) the upper energy limit for which the NEGF is computed in the nanotube
- Elower : (double) the lower energy limit for which the NEGF is computed in the nanotube
- dE : (double) the energy step computed when solving the NEGF
- thop : (double) the hopping parameter of the pz tight-binding Hamiltonian
- eta : (double) the infinitesimal imaginary part used in the NEGF formalism
- mu1 : (double) the Fermi level of the left reservoir
- mu2 : (double) the Fermi level of the right reservoir
- Temp : (double) the temperature of the nanotube
- contact : (string) can assume either the values “doped” or “Schottky”. If “doped”, semi-infinite nanotubes are connected at both channel ends, repeating to the infinite the potential at the ends of the nanotube. If “Schottky”, Schottky contacts are taken into account.
- E : (numpy array) array of the energies for which the transmission coefficient and the free charge is computed in the nanotube by means of the NEGF formalism
- T : (numpy array) array of the transmission coefficient computed in correspondence of the energies stored in the E array
- charge : (numpy array of length n*Nc) free charge computed in correspondence of each C atom of the nanotube.
- x : (numpy array of length n*Nc) the x position of the i-th atom of the nanotube
- y : (numpy array of length n*Nc) the y position of the i-th atom of the nanotube
- z : (numpy array of length n*Nc) the z position of the i-th atom of the nanotube
- atoms_coordinates : (function) it computes the atoms coordinates in correspondence of each C atoms, filling the x, y, z vectors of the nanotube class
- Nmodes : (int) the number of modes, when solving NEGF in the mode space
- L : (double) the effective length of the nanotube, which is the length of the nanotube composed by a integer number + 0.5 of unit cells, closest to the length specified by the user.
- charge_T : (function) function which computes the free charge and the transmission coefficient in the energy interval specified by Eupper and Elower with an energy step equal to dE in correspondence of each C atoms of the nanotube. Such a computation is performed in the real space.
- mode_charge_T : (function) function which computes the free charge and the transmission coefficient in the energy interval specified by Eupper and Elower with an energy step equal to dE, in correspondence of each C atoms of the nanotube. Such computation is performed in the mode space, using a number of transversal modes equal to Nmodes.
- current : (function) it computes the current through the Landuer formula, once filled the T vector
- gap : (function) it computes the energy gap of the nanoribbon.
- rank : (int) the rank of the process
See the tutorial on nanotube for a clear understanding of this class.