Synopsys: Hamiltonian(n,Nc)
Hamiltonian is the NanoTCAD ViDES class, which allow the definition of a general Hamiltonian within the semi-empirical tight-binding model. As inputs, it requires the number of atoms n in the slice, and the number of slices Nc of the material to be considered. Nc must be at least larger than 4. For a complete understanding of such quantities, please refer to Tutorial 09.
The attributes of the classes are the following:
- Nc : (int) the number of slices
- n : (int) the number of atoms within each slice
- x: (numpy array of length n*Nc) x coordinates of the atoms
- y: (numpy array of length n*Nc) y coordinates of the atoms
- z: (numpy array of length n*Nc) z coordinates of the atoms
- Phi: (numpy array of length n*Nc) potential of the atoms
- Eupper : (double) the upper energy limit for which the NEGF is computed in the nanoribbon
- Elower : (double) the lower energy limit for which the NEGF is computed in the nanoribbon
- dE : (double) the energy step computed when solving the NEGF
- 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 nanoribbon
- E : (numpy array) array of the energies for which the transmission coefficient and the free charge is computed in the nanoribbon 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 nanoribbon.
- 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 nanoribbon. Such a computation is performed in the real space.
- H : (numpy matrix) the Hamiltonian stored in the VHF format.