TeNPy Forum

Hi! I am also looking into the scaling of S with \log \xi to extract the central charge and from what I read the relation you originally posted S \approx \frac{c}{6}\log \xi should be the correct one even for iDMRG. Apart from Calabrese and Cardy's original paper, here is a reference where they do i...

Hi! This is the function modified according to your useful suggestions: def _term_to_jw(self, term, op_string = "JW"): """Given a term that is a tensor product of several operators acting on possibly non-neighboring sites [i_min, ... i_n, ... , i_max], this puts Jordan-Wigne...

I implemented this function that takes a term containing operators acting on non-neighbouring sites and returns a list of operators, obtained by filling the intermediate sites with "Id" or "JW" where appropriate. The output can be used by the method expectation_value_multi_sites ...

I am developing the method that, given a MPS in canonical form, calculates the expectation value of multi-site operators that are tensor product of one-site operators. This is what I implemented so far: it works but does not handle operator strings (like the Jordan-Wigner string that is needed in th...

I did some tests myself and i reached the same conclusion, that the MPO matrices give the correct Hamiltonian once multiplied together (I also tried explicitly for Ly = 3). I used the MPO matrices of TeNpy's toric-code model to create another toric-code model using the grid_outer method. For Lx=1, L...

Oh I just saw your previous reply. Indeed, for L_y = 2 we get the same answers. The problem seems to be when L_y is odd.

I tested your code a bit more and compared to mine, setting L_x = 1 in both cases (as we agree, it should not matter). What I found out is that the results coincide exactly with mine whenever L_y is even, and fails otherwise (e.g. the energy depends on L_x , the bond dimension is always saturated, e...

Hi [mention]Johannes[/mention] . I am looking at how the multi-coupling model works. However I have a quick question specific to the toric code example. What is L_x, when the boundary conditions are set to "infinite" (infinite cylinder)? I thought it would be just a repetition of the unit ...