English

Use and implementation of autodifferentiation in tensor network methods with complex scalars

Strongly Correlated Electrons 2019-09-27 v2

Abstract

Following the recent preprints arXiv:1903.09650 and arXiv:1906.04654 we comment on the feasibility of implementation of autodifferentiation in standard tensor network toolkits by briefly walking through the steps to do so. The total implementation effort comes down to fewer than 1000 lines of additional code. We furthermore summarise the current status when the method is applied to cases where the underlying scalars are complex, not real and the final result is a real-valued scalar. It is straightforward to generalise most operations (addition, tensor products and also the QR decomposition) to this case and after the initial submission of these notes, also the adjoint of the complex SVD has been found.

Cite

@article{arxiv.1907.13422,
  title  = {Use and implementation of autodifferentiation in tensor network methods with complex scalars},
  author = {Claudius Hubig},
  journal= {arXiv preprint arXiv:1907.13422},
  year   = {2019}
}

Comments

11 pages, 1 figure; include reference to recently found adjoint of SVD

R2 v1 2026-06-23T10:35:53.062Z