Dear Gabriel, You have a "Dimensionality mismatch": Use the same dimension for the two lattices. If you are still using two different lattices, then go and check the FAQ [1] where you have a nice example about combining graphene with a square lattice.
I hope this helps, Adel [1] https://kwant-project.org/doc/1/tutorial/faq On Tue, Jun 6, 2023 at 5:55 PM Gabriel Garcia <gqgarci...@gmail.com> wrote: > Hi devs, > > I am learning kwant alone, but i have doubts. I am trying to construct a > system with a diatomic chain as scattering region and the leads as a > monoatomic chain. But i am doing something wrong. Someone else can help me? > Bellow i will show the code: > > > ##################################################################################################################### > from matplotlib import pyplot as plt > from matplotlib import backends > import kwant > > # Defining the parameters > L = 5 # range of scattering region > C = 2 # primitive vector > # Definindo o parametro de Hopping > > t = 5 # hopping parameter > > lat = kwant.lattice.general([(C,0),(0,1)],[(0,0),(1,0)], norbs=1) > a, b = lat.sublattices > > syst = kwant.Builder() > > # Scattering region > for i in range(L): > syst[a(i, 0)] = 0 > syst[b(i, 0)] = 0 > > syst[kwant.builder.HoppingKind((0, 0), a, b)] = -t > syst[kwant.builder.HoppingKind((1, 0), b, a)] = -t > > kwant.plot(syst) > plt.show() > > # leaft lead (lead 1) > lat_lead1 = kwant.lattice.chain(C, norbs=1) > sym_lead1 = kwant.TranslationalSymmetry((-C, 0)) > > lead1 = kwant.Builder(sym_lead1) > > lead1[lat_lead(0,0)] = 4*t > lead1[lat_lead1.neighbors()] = -t > > syst[(lat_lead1(-C, 0), a(0, 0))] = -t > > syst.attach_lead(lead1) > > kwant.plot(syst) > > --------------------------------------------------------------------------- > ValueError Traceback (most recent call last) > ~\anaconda3\lib\site-packages\kwant\builder.py in __new__(cls, family, > tag, _i_know_what_i_do) > 75 try: > ---> 76 tag = family.normalize_tag(tag) > 77 except (TypeError, ValueError) as e: > > ~\anaconda3\lib\site-packages\kwant\lattice.py in normalize_tag(self, tag) > 475 if len(tag) != self.lattice_dim: > --> 476 raise ValueError("Dimensionality mismatch.") > 477 return tag > > ValueError: Dimensionality mismatch. > > During handling of the above exception, another exception occurred: > > ValueError Traceback (most recent call last) > <ipython-input-46-3d36b05d2870> in <module> > 8 lead1[lat_lead1.neighbors()] = -t > 9 > ---> 10 syst[(lat_lead1(-C, 0), a(0, 0))] = -t > 11 > 12 syst.attach_lead(lead1) > > ~\anaconda3\lib\site-packages\kwant\builder.py in __call__(self, *tag) > 195 raise ValueError('Use site_family(1, 2) instead of ' > 196 'site_family((1, 2))!') > --> 197 return Site(self, tag) > 198 > 199 > > ~\anaconda3\lib\site-packages\kwant\builder.py in __new__(cls, family, > tag, _i_know_what_i_do) > 77 except (TypeError, ValueError) as e: > 78 msg = 'Tag {0} is not allowed for site family {1}: {2}' > ---> 79 raise type(e)(msg.format(repr(tag), repr(family), > e.args[0])) > 80 return tuple.__new__(cls, (family, tag)) > 81 > > ValueError: Tag (-2, 0) is not allowed for site family > kwant.lattice.Monatomic([[2.0]], [0.0], '', 1): Dimensionality mismatch. > > > ############################################################################################# > Thanks! > Gabriel Garcia > -- Abbout Adel
