Attatchment: test code for calculating lls of monolayer graphene
hamiltonian = """
+ hbar_vF * (k_x * kron(sigma_0, sigma_x) + k_y * kron(sigma_0,
sigma_y))
"""
params = dict(hbar_vF=6.582)
syst = kwant.continuum.discretize_landau(hamiltonian, N=20)
syst = syst.finalized()
b_values = np.linspace(0, 0.00002, 200)
fig = kwant.plotter.spectrum(syst, ('B', b_values), params=params,
show=False,file = 'example.png')
fig.savefig('example.png')
