TeNPy Forum

Thank you very much for the answer. I calculated the time evolution for a t that provides me with a sufficient frequency resolution (for first tests in any case). However, I’m still concerned with the technicality that I mentioned above that I get the Error ‘incompatible leg charge’ when I want to c...

So I guess the problem is that the maximal bond dimensions of the iDMRG ground state psi_0, and the time evolved ground state psi are different. I passed the same chi_max to both algorithms, but since psi_0 is closer to a product state it doesn't need a very high chi. Is there a way to 'grow' psi_0 ...

Quick Follow-up question: So I guess the code to obtain the structure factor C^zz_ij could look something like this (already having calculated the iDMRG ground state psi_0): C_ij = [] for site in range(num_sites): # apply the first operator to the ground state psi = psi_0.copy() psi.apply_local_op(s...

I see, thanks for your help!
Best regards!

Thanks a lot. I was a little overwhelmed with the many possibilities, but I settled on trying out ExpMPOEvolution.
In the last step, why should I use mpsenvironment.expectation_value instead of the mps.method?

Within some approximation a system has the ground state |\tilde{\psi}_0 \rangle and an excited state |\tilde{\psi}_1 \rangle = \hat{O}|\tilde{\psi}_0 \rangle that is connected via the operator \hat{O} , which is known. I now did a DMRG calculation for that system, obtaining the real ground state |\p...

Hello, I would like to calculate the Dynamical Spin Structure and/or the Excitation spectrum of the 2 chain spin ladder, which I implemented below.Ultimately, I would like to compare the results to Neutron Scattering experiments. Using the ladder lattice of TenPy I constructed the model: class spinL...