GroupTheory`

GTTbTubeBands

GTTbTubeBands[ham,n,m,{kpath,names}] calculates the band structure of an (n,m) carbon nanotube along kpath with the names for the symmetry points in k-space. ham is the Hamiltonian of a graphene layer.

Details and Options

The following options can be used

GOVerbose	True	Controls the output of additional information
GOPlotBands	True	Controls calculation of bands in the Brillouin zone
GOTbOrthogonal	True	Controls if the calculation is a standard or general eigenvalue problem.
GOStore	0	Controls output of bands and eigenvalues to files.

See: W. Hergert, M. Geilhufe, Group Theory in Solid State Physics and Photonics. Problem Solving with Mathematica, chapter 9.7

Examples

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Basic Examples (1)

First load the package:

Read the Hamiltonian of graphene.

THe Hamiltonian is already parametrized.

Options (4)

GOVerbose (1)

Additional information can be switched off. This might be interesting if GTTbTubeBands is used inside a larger module.

GOPlotBands (1)

The option GOPlotBands->False is usually used, if data for the calculation of DOS are prepared.

GOTbOrthogonal (1)

In a non-orthogonal TB problem the Hamiltonian matrix and the overlap matrix define a general eigenvalue problem. As a simple example the orthogonal eigenvalue problem will be considered as a non-orthogonal one, providing a identity matrix as overlap matrix.

The results have to be the same as before.

GOStore (1)

The results of the calculation can be stored in a file for later use.