Dear, M. Dolfi
I am a freshman about DMRG. I have two questions : (1) How to get truncation error using mps_optim codes ? (2) How to get von Neumann entanglement entropy S(A) of a system A. Actually, I have obtained entanglement entropy data by setting MEASURE[Entropy]=1 using mps_optim. For a spin chain, we got the data number of entanglement entropy which seems the same as the number of 'bond' in chain. For example, to run a mps_optim of a spin chain with 32 sites , I will get 31 data in output of entropy. What meaning of such entanglement entropy data? How to get von Neumann entanglement entropy S(A) of a two dimension system A (Just like page 5 in paper Phys.Rev.B 64,024424(2012))
L.J.Meng
Xiangtan University ------------------