Non-interacting band structure

%matplotlib inline
import numpy as np
from quant_met import geometry, mean_field, plotting

square_lattice = geometry.SquareLattice()
n = 1000  # number of points across the whole k space path
band_path, band_path_plot, ticks, labels = square_lattice.generate_high_symmetry_path(
    number_of_points=n
)

BZ_path_plot = plotting.scatter_into_bz(square_lattice.bz_corners, band_path)

square_h = mean_field.OneBandTightBindingHamiltonian(
    hopping=1,
    lattice_constant=square_lattice.lattice_constant,
    chemical_potential=0,
    hubbard_int=4,
    delta=np.array([1]),
)

bdg_h = square_h.bdg_hamiltonian(k=np.array([np.array([0, 0]), np.array([1, 1])]))

band_structure = square_h.calculate_bandstructure(band_path)

fig = plotting.plot_bandstructure(
    bands=band_structure[["band"]].to_numpy().T,
    k_point_list=band_path_plot,
    labels=labels,
    ticks=ticks,
)

solved_h = mean_field.self_consistency_loop(h=square_h, number_of_k_points=100, epsilon=1e-9)

Old: [79.6420723]
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81.64142964276546
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3.5546665
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2.9898653
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2.7735229
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2.7423697
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2.7421522
Finished

bdg_bands, bdg_wavefunctions = solved_h.diagonalize_bdg(k=band_path)

fig = plotting.plot_bandstructure(
    bands=bdg_bands.T,
    k_point_list=band_path_plot,
    labels=labels,
    ticks=ticks,
)