Link ID different for left and right orthogonal tensors

[jake]

Hi Everyone,

I’m working with the InfiniteMPS package, and I’m running into a small issue with the links of the tensors of a state psi. Put briefly, the right orthogonalized tensors,

psi.AR[0]

do not have the same link index IDs as the tensors of the InfiniteCanonicalMPS psi, while the tensors of psi.AL
do have matching indices. Is this a bug? Should I just manually relabel the indices of psi.AR for now? Thanks!

Best,
Jake

[ryanlevy]

The indices are labeled correctly, and are “off” by applications of psi.C

julia> inds(dense(ψ.AR[1]*ψ.C[0]*ψ.AR[2]))
((dim=2|id=597|"S=1/2,Site,c=1,n=1"), 
(dim=100|id=515|"Link,c=0,l=2"), 
(dim=2|id=58|"S=1/2,Site,c=1,n=2"), 
(dim=100|id=341|"Link,c=1,l=2"))

julia> inds(dense((ψ.AL[1]*ψ.AL[2]*ψ.C[2])))
((dim=2|id=597|"S=1/2,Site,c=1,n=1"), 
(dim=100|id=515|"Link,c=0,l=2"), 
(dim=2|id=58|"S=1/2,Site,c=1,n=2"), 
(dim=100|id=341|"Link,c=1,l=2"))

Is there something you’re trying to do and finding the indices aren’t working out?

[jake]

Thanks that makes sense now. In general I’m working on excited states and it requires various contractions of the right orth tensors with tensors that have indices that I’ve initialized to match the original tensors of psi[0]. I can just create a new tensor with the indices relabeled and use that instead.