TeNPy Forum

Hi, This question deals with somewhat uncommon usage of the np_conserved module. I would greatly appreciate help, as I suspect there may be a bug with the npc.detect_legcharge function. I am using the np_conserved module to create my own MPO. The purpose is to simulate a layer of two qubit gates. Su...

Hi, If I have a purification MPS representing a finite temperature thermal mixed state \rho , is there an efficient way I can compute the purity Tr[\rho^2] of the thermal state? I am not sure if there is even a way to compute moments of the actual thermal state from the pure MPS in the purified spac...

Hello, I have an MPS for which I want to simulate time evolution, but the time evolution I seek is by evolving under two different Hamiltonians H_1 and H_2 . I want to evolve under U_1=exp(-iH_1t) on the subsystem composed of sites 0,2,4,...L-1, and U_2=exp(-iH_2t) on the subsystem composed of sites...

Hello, This is a general question about the validity of different algorithms for gapless systems and how to get reasonable results from tensor network methods for such systems. I am trying to find the ground state of a system with a gap that closes at least as fast as O(1/N^2) for system size N. I a...

Hi Johannes, Thank you so much for your response, this is really helpful! Also I now realize how the open legs in the diagram might have been confusing - I intended for the dangling legs to indicate periodic contraction, not that they are open. Sorry for the confusion - I do in fact want the periodi...

Hi, I am wondering, given finite boundary condition MPSs |M1>, |M2>, how I can compute the inner product <M1|T^n|M2>,, where T is the translation operator (to the right), by one site. For example, for n=1, I want to do the following contraction: M11 - M12- M13- ..... M1(N-1) - M1N \ \ \ \ \ \ M21 - ...