TeNPy Forum

Am I right that one has to reload preloaded modules like numpy/scipy after setting the number of threads or is there any other way to do that? I don't think you need to reload scipy or numpy. It's still the same library, using the same underlying MKL, it's just a sinlge parameter, which can be chan...

Hi Mirco, I see, so they are basically the same in the limit of half as many nodes as sites. I wonder whether the full parallelization of Ueda's approach requires more or less iterations/sweeps to reach convergence. As far as I see, compared to the sweeping it needs more (two-site) updates to carry ...

Hey Mirco, parallelization of DMRG is a great idea which will probably benefit many people! Using mpi4py seems a good idea to me. As you said, it's included in the intel python distribution, and also in the anaconda distribution - these two are the recommended ones in the installation instructions, ...

As we are contracting the entire MPS to calculate for energy, is my understanding correct in saying that it does not matter which site we choose in this case? Yes, that's correct! Based on what I understand, iDMRG can still be calculated for such a system but the only way to obtain the energy is di...

Taking the energy as returned by the DMRG code is a perfectly reasonable thing ;-) And it's what I would recommend you for now. In general, you could still try to get the energy from local expectation values and/or correlation functions, but you would need to carefully figure all the terms out and s...

On one hand I agree that this would be very cool to have an single "TFIModel" with some specified nearest neighbor couplings. On the other hand, I see some problems with that: When you only want to derive the Model from the MPOModel, this approach is fine, but what if you want to derive fr...

ok, which initial state and parameters are you using? Mixer enabled? I checked with the following code import numpy as np from tenpy.models.toric_code import ToricCode from tenpy.networks.mps import MPS from tenpy.algorithms import dmrg for Lx in [1, 2, 3, 4]: print("="*80) print("Lx ...

You're right, L_x is just the number of "rings" of the cylinder included into the MPS unit cell. I agree that the energy per site shouldn't depend on L_x, so it's a bad sign if it does, there's probably something wrong then

To answer first in general (That's the perfect place to ask this ;-)): If you give the strength parameter to add_coupling , it is tiled to the "correct" size of the couplings. You are right, for onsite terms in add_onsite , this is simply the Ls of the lattice. Now what is the "correc...

Since I've recently added the MultiCouplingModel , it's time to add a simple model actually using it. I think the exactly solvable toric code is a good example, so here is my implementation: """Kitaev's exactly solvable toric code model. As we put the model on a cylinder, the name &qu...

It's a bit wired to make the announcement that I've set up this forum in this forum, but I guess that's the first thing to announce to the world once this forum is set up
Anyways, I'm awaiting your questions, suggestions and contributions. Happy posting!