18 lines
611 B
Python
18 lines
611 B
Python
import guan
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import numpy as np
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from math import *
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def hamiltonian_function(kx, ky): # one QAH model with chern number 2
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t1 = 1.0
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t2 = 1.0
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t3 = 0.5
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m = -1.0
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hamiltonian = np.zeros((2, 2), dtype=complex)
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hamiltonian[0, 1] = 2*t1*cos(kx)-1j*2*t1*cos(ky)
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hamiltonian[1, 0] = 2*t1*cos(kx)+1j*2*t1*cos(ky)
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hamiltonian[0, 0] = m+2*t3*sin(kx)+2*t3*sin(ky)+2*t2*cos(kx+ky)
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hamiltonian[1, 1] = -(m+2*t3*sin(kx)+2*t3*sin(ky)+2*t2*cos(kx+ky))
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return hamiltonian
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chern_number = guan.calculate_chern_number_for_square_lattice(hamiltonian_function, precision=100)
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print(chern_number) |