Hi Miles,

I am trying to look at dynamical quantum phase transitions (DQPTs) in a particular model by numerically finding Fisher zero lines @@z \in \mathcal{C} @@ such that @@\langle \psi (0) | \psi (z) \rangle = 0@@, where @@ | \psi (z) \rangle := e^{zH} | \psi (0) \rangle@@.

I would like to work directly in the thermodynamic limit using iDMRG code based on this example, and identify Fisher zeros based on crossings in the eigenspectrum of the Transfer Matrix. How would I compute the transfer matrix of two MPS and obtain its eigenvalues, similarly to what is done in TenPy?

Also, are there any subtleties I need to be aware of when performing real and imaginary time evolution of iMPS in ITensor, or can I use the same functionality as for generic MPS?

Thanks so much for your help!