I have a question concerning the leads. Suppose that I am considering a n-p-n or p-n-p junction, where the scattering region (assumed with a cubic geometry) is attached to two leads (say along the direction y) having the same Hamiltonian but different onsite energy. In the scattering region, a nearest-neighbor hopping occurs along \hat{y} c_{i + \hat{y}}^{\dagger} M c_{i} + H.c., with a matrix M not Hermitian in general. Going to attach the leads, I have a doubt if M is not Hermitian. Indeed, I think I can still write for the right lead: sym_right_lead = kwant.TranslationalSymmetry((0, a, 0)) right_lead = kwant.Builder(sym_right_lead) for i in range(W): for k in range(W): right_lead[lat(i, 1, k), lat(i, 0, k)] = M syst.attach_lead(right_lead) However, for the left lead I have the doubt between sym_left_lead = kwant.TranslationalSymmetry((0, -a, 0)) left_lead = kwant.Builder(sym_left_lead) for i in range(W): for k in range(W): left_lead[lat(i, 1, k), lat(i, 0, k)] = M syst.attach_lead(left_lead) and the same code with M^{dagger}: left_lead[lat(i, 1, k), lat(i, 0, k)] = M^{\dagger} (or, I guess, equivalently the form in terms of the interchanged hopping: left_lead[lat(i, 0, k), lat(i, 1, k)] = M). Between the two options, nothing changes in the spectrum of the leads (fine !), but I does for the conductance of the junction. Can you help me ? Thank you very much L. L.
participants (2)
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Abbout Adel
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Luca Lepori