update_again

Tutorial/calculate_density_of_states.py

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+import guan
+import numpy as np
+
+# calculate density of states
+hamiltonian = guan.finite_size_along_two_directions_for_square_lattice(2,2)
+fermi_energy_array = np.linspace(-4, 4, 400)
+total_dos_array = guan.total_density_of_states_with_fermi_energy_array(fermi_energy_array, hamiltonian, broadening=0.1)
+guan.plot(fermi_energy_array, total_dos_array, xlabel='E', ylabel='Total DOS', type='-o')
+
+fermi_energy = 0
+N1 = 3
+N2 = 4
+hamiltonian = guan.finite_size_along_two_directions_for_square_lattice(N1,N2)
+LDOS = guan.local_density_of_states_for_square_lattice(fermi_energy, hamiltonian, N1=N1, N2=N2)
+print('square lattice:\n', LDOS, '\n')
+h00 = guan.finite_size_along_one_direction(N2)
+h01 = np.identity(N2)
+LDOS = guan.local_density_of_states_for_square_lattice_using_dyson_equation(fermi_energy, h00=h00, h01=h01, N2=N2, N1=N1)
+print(LDOS, '\n\n')
+# guan.plot_contour(range(N1), range(N2), LDOS)
+
+N1 = 3
+N2 = 4
+N3 = 5
+hamiltonian = guan.finite_size_along_three_directions_for_cubic_lattice(N1, N2, N3)
+LDOS = guan.local_density_of_states_for_cubic_lattice(fermi_energy, hamiltonian, N1=N1, N2=N2, N3=N3)
+print('cubic lattice:\n', LDOS, '\n')
+h00 = guan.finite_size_along_two_directions_for_square_lattice(N2, N3)
+h01 = np.identity(N2*N3)
+LDOS = guan.local_density_of_states_for_cubic_lattice_using_dyson_equation(fermi_energy, h00, h01, N3=N3, N2=N2, N1=N1)
+print(LDOS)