Dear Yl, I guess this is related to the discretization of the hamiltonian in a square lattice. In tight binding, we often wind up with many issues while descritizing the Dirac Hamiltonian in a square lattice. In the continuum model, it works fine but in tight binding it does not and often winds up with degeneracy that might be related to the doubling fermion. Best Adel
Le mar. 18 juin 2024 à 16:51, yl <ac76...@sjtu.edu.cn> a écrit : > Dear Kwant Group, > > I attempted to replicate the Landau levels of ABA-trilayer graphene as > described in the paper "Landau level spectra and the quantum Hall effect of > multilayer graphene," Physical Review B 83, 165443 (2011), Figure 2, using > Kwant. The results obtained with Kwant match the paper's results > approximately well; however, there is an issue. The number of Landau levels > (LLs) under each magnetic field does not match the results presented in the > paper. For example (see the attached figure): > > At a magnetic field strength of ( B = 10 ) Tesla: > > The left figure shows a total of 46 LLs (18 + 28). > The right figure shows a total of 34 LLs (16 + 18). > For the specific cases labeled as 'a' to 'd', each of these cases has 2 > more LLs compared to a reference. > > For the case labeled 'e', this case has 4 more LLs compared to a reference. > > I believe the reference is correct as I was able to reproduce the > completely identical LLs results using WannierTools(an open source code > which can calculate LLs by Peierls substitution method). > > I am currently unsure where the problem lies or if it is a bug. I have > attached the code (test.py) and a small modification to the spectrum > function in plotter.py. > > Thank you very much to the Kwant development team for your efforts. I hope > to get an answer, as it would be very helpful to me. > > Versions used: 1.4.3 + landau_levels.py > > Best regards, > > ac76888 > > ac76...@sjtu.edu.cn
