Source code for tbmodels.helpers

#
# (c) 2015-2018, ETH Zurich, Institut fuer Theoretische Physik
# Author: Dominik Gresch <greschd@gmx.ch>
"""
This module contains a helper function to create a list of hoppings from a given matrix (:meth:`matrix_to_hop`).
"""

import typing as ty

import numpy as np
from fsc.export import export


[docs]@export def matrix_to_hop( mat: ty.Sequence[ty.Sequence[complex]], orbitals: ty.Optional[ty.Sequence[int]] = None, R: ty.Sequence[int] = (0, 0, 0), multiplier: float = 1.0, ) -> ty.List[ty.List[ty.Union[complex, int, np.ndarray]]]: r""" Turns a square matrix into a series of hopping terms. Parameters ---------- mat : The matrix to be converted. orbitals : Indices of the orbitals that make up the basis w.r.t. which the matrix is defined. By default (``orbitals=None``), the first ``len(mat)`` orbitals are used. R : Lattice vector for all the hopping terms. multiplier : Multiplicative constant for the hopping strength. """ if orbitals is None: orbitals = list(range(len(mat))) hop = [] for i, row in enumerate(mat): for j, x in enumerate(row): hop.append( [ multiplier * x, orbitals[i], orbitals[j], np.array(R, dtype=int), ] ) return hop