Dear ITensor community,

I would like to ask for help with the following problem:

For a 1D boson-chain psi I would like to consider situation:

Let's us define operator

"auto Sy = 0.5/Cplx_i*( sites.op("Adag",i)*sites.op("A",j) - sites.op("Adag",j)*sites.op("A",i))"Let's us define its exponential

"auto expSy = expHermitian(Sy, -Cplx_i*Y);"

I would like to define such an operation:

```
"psi_i_j:= expSy*psi_i_j",
```

i.e. rotation between sites {i,j} by angle Y. I know that to extract a single physical index I should use, psi.Aref(i), however, I stuck in the construction of a rotation itself.

Many thanks in advance,

Marcin