sisl.physics.SemiInfinite

class sisl.physics.SemiInfinite(spgeom, infinite: Literal['+A', '-A', '+B', '-B', '+C', '-C'], eta: float = 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 (\(\eta\)) of the self-energy calculation

Methods

`broadening_matrix`(args, *kwargs)	Calculate the broadening matrix by first calculating the self-energy
`se2broadening`(SE)	Calculate the broadening matrix from the self-energy
`self_energy`(args, *kwargs)

__init__(spgeom, infinite: Literal['+A', '-A', '+B', '-B', '+C', '-C'], eta: float = 0.0001)[source]

Create a SelfEnergy object from any SparseGeometry

Parameters:

infinite (Literal['+A', '-A', '+B', '-B', '+C', '-C'])
eta (float)

broadening_matrix(*args, **kwargs)

Calculate the broadening 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 broadening matrix.

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

For a huge performance boost, please do:

>>> SE = SelfEnergy(...)
>>> self_energy = SE.self_energy(0.1)
>>> gamma = SE.se2broadening(self_energy)

Notes

When using both the self-energy and the broadening matrix please use se2broadening after having calculated the self-energy, this will be much, MUCH faster!