TeNPy Forum

I am studying a model with iDMRG and was wondering if I can extract correlation functions using iDMRG? I am interested in studying the possibility of a superconducting phase by studying the correlators. My initial lattice size is 2 (before iDMRG run). Also, is it possible to extract central charge using iDMRG? I have also tried analyzing my model using DMRG but it is difficult for it to converge.

Any suggestion will be really helpful.

Yes, even if the MPS unit cell is 2, you can have correlations in the MPS way beyond those 2 sites.
You can for example call correlation_function with sites2=range(50) to calculate correlations up to site 50, or term_correlation_function_right.

And yes, you can also extract the central charge by a careful scaling analysis of the entanglement vs log(bond dimension), as illustrated in central_charge_ising.py, see also arXiv:0812.2903 (referenced in the example as pollman2009).