# sisl.physics.SemiInfinite

class sisl.physics.SemiInfinite(spgeom, infinite, eta=0.0001)

Bases: SelfEnergy

Self-energy object able to calculate the dense self-energy for a given SparseGeometry in a semi-infinite chain.

Parameters
• spgeom (SparseGeometry) – any sparse geometry matrix which may return matrices

• infinite (str) – axis specification for the semi-infinite direction (+A/-A/+B/-B/+C/-C)

• eta (float, optional) – the default imaginary part of the self-energy calculation

Methods

 scattering_matrix(*args, **kwargs) Calculate the scattering matrix by first calculating the self-energy Calculate the scattering matrix from the self-energy self_energy(*args, **kwargs)
__init__(spgeom, infinite, eta=0.0001)[source]

Create a SelfEnergy object from any SparseGeometry

scattering_matrix(*args, **kwargs)

Calculate the scattering matrix by first calculating the self-energy

Any arguments that is passed to this method is directly passed to self_energy.

See self_energy for details.

This corresponds to:

$\boldsymbol\Gamma = i(\boldsymbol\Sigma - \boldsymbol \Sigma ^\dagger)$

Examples

Calculating both the self-energy and the scattering matrix.

>>> SE = SelfEnergy(...)
>>> self_energy = SE.self_energy(0.1)
>>> gamma = SE.scattering_matrix(0.1)


For a huge performance boost, please do:

>>> SE = SelfEnergy(...)
>>> self_energy = SE.self_energy(0.1)
>>> gamma = SE.se2scat(self_energy)


Notes

When using both the self-energy and the scattering matrix please use se2scat after having calculated the self-energy, this will be much, MUCH faster!

se2scat

converting the self-energy to the scattering matrix

self_energy

the used routine to calculate the self-energy before calculating the scattering matrix

static se2scat(SE)

Calculate the scattering matrix from the self-energy

$\boldsymbol\Gamma = i(\boldsymbol\Sigma - \boldsymbol \Sigma ^\dagger)$
Parameters

SE (matrix) – self-energy matrix

self_energy(*args, **kwargs)