I am trying to reproduce the paper following.

https://arxiv.org/abs/1110.4280 (in this paper, fig5, 6 will help to understand my questions.)

What I’m struggling with now is to build a finite(not infinite, and not having any translational symmetry) lead as below.

1. I think "kwant.builder.SelfEnergyLead()” function might be proper thing to build a finite lead without any translational symmetry. Is it correct?

2. If it's right, when I run this code using SelfEnergyLead(), the following error occurs. How can I solve it?

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lat = kwant.lattice.chain(norbs=1)

syst = kwant.Builder()

syst[(lat(i) for i in range(4))] = 4

syst[lat.neighbors()] = -1

def self_energy(energy, args=(), *, params=None):

return -1j

left_lead = kwant.builder.SelfEnergyLead(self_energy, interface=[lat(0)], parameters = [])

right_lead = kwant.builder.SelfEnergyLead(self_energy, interface=[lat(3)], parameters = [])

syst.leads.append(left_lead)

syst.leads.append(right_lead)

syst = syst.finalized()

H = syst.leads[0].kwant.hamiltonian_submatrix

kwant.plot(syst)

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AttributeError: 'SelfEnergyLead' object has no attribute ‘kwant'

Any help is appreciated!