Two site reduced density matrix for two distant apart sites

[kaushman1996]

Hi Is there any easy way to get two site reduced matrix for two distant part sites?

[jurajHasik]

Hi,

see https://peps-torch.readthedocs.io/en/latest/envs/generic/corrf.html

But only correlations along horizontal r=(x,0) or vertical r=(0,y) direction can be computed in this way. Arbitrary coordinates for correlations, i.e. <O(0)O(r)> where r=(x,y) cannot computed as easily/efficiently due to CTM environments.