Convenience Parameter Setting#

elecboltz.easy_params(params)#

Convenience function to set parameters for the simulation.

List of convenience features:

  • Set unit cell dimensions with named parameters a, b, and
    c. If b or c are not given, they are assumed to be equal
    to a.

  • Define an energy_scale which scales all energy parameters.

  • Set the chemical potential with mu in band_params. If mu
    is set in band_params, it is assumed the energy dispersion is
    shifted by the chemical potential, so the associated variable
    is set to 0.0 in the returned parameters.
  • Set the dispersion relation with a default tight-binding model.
    See get_tight_binding_dispersion for the list of parameters
    and the resulting expression.
  • Build the scattering function using predefined
    scattering_models and the scattering_params associated with
    them. See build_scattering_function for supported scattering
    models and their parameters. scattering_models is assumed to
    be only one isotropic model if not specified.
Parameters:

params (dict) – Simplified (easy-to-use) parameters for the simulation.

Returns:

Parameters compatible with the classes in the package.

Return type:

dict

elecboltz.params.get_tight_binding_dispersion(band_params) → str#

Get the tight-binding dispersion relation containing terms relating to the parameters in band_params.

The full tight-binding dispersion relation is given by:

-mu - 2*t * (cos(a*kx)+cos(b*ky))
- 4*tp * cos(a*kx)*cos(b*ky)
- 2*tpp * (cos(2*a*kx)+cos(2*b*ky))
- 2*tz * (cos(a*kx)-cos(b*ky))**2
    * cos(a*kx/2)*cos(b*ky/2)*cos(c*kz/2)

The list of parameters is as follows:

  • mu: Chemical potential.

  • t: Nearest-neighbor hopping parameter in the x-y plane.

  • tp: Next-nearest-neighbor hopping parameter in the x-y plane.

  • tpp: Next-next-nearest-neighbor hopping parameter
    in the x-y plane.
  • tz: Nearest-neighbor hopping parameter between
    the different layers in the z direction.
Parameters:

band_params (dict or set) – Dictionary or set of parameters for the tight-binding model.

Returns:

The dispersion relation expression string

Return type:

str