Models

Here we define some models, that can be used to test the code, or just to play around

wannierberri.models.Chiral(delta=2, hop1=1, hop2=0.3333333333333333, phi=0.3141592653589793, hopz_right=0.0, hopz_left=0.2, hopz_vert=0.0)[source]
Create a chiral model - a chirally stacked haldane model -

using PythTB Following the article by Yoda,Yokoyama & Murakami 2018 this model breaks time-reversal and inversion, so it can be used to test almost any quantity. Has a symmetry C3z

Parameters:
  • delta (float) – difference between the on-site potentials of the two atoms

  • hop1 (float) – nearest-neighbour in-plane hopping

  • hop2 (float) – magnitude of next nearest-neighbour in-plane hopping

  • phi (float) – phase of next nearest-neighbour in-plane hopping

  • hopz_vert (float or complex) – interlayer vertical hopping

  • hopz_right (float or complex) – chiral right-handed hopping in the z direction

  • hopz_left (float or complex) – chiral left-handed hopping in the z direction

  • Note

  • --------

  • pythtb) (PythTB should be installed to use this (pip install)

wannierberri.models.Haldane_ptb(delta=0.2, hop1=-1.0, hop2=0.15, phi=1.5707963267948966)[source]

same as Haldane_tbm(), but uses PythTB

Note:

PythTB should be installed to use this (pip install pythtb)

wannierberri.models.Haldane_tbm(delta=0.2, hop1=-1.0, hop2=0.15, phi=1.5707963267948966)[source]

Defines a Haldane model within TBmodels

Parameters:
  • delta (float) – difference between the on-site potentials of the two atoms

  • t (float) – nearest-neighbour hopping

  • hop2 (float) – magnitude of next nearest-neighbour hopping

  • phi (float) – phase of next nearest-neighbour hopping

  • Note

  • --------

  • tbmodels) (TBmodels should be installed to use this (pip install)