toExpH for 3spin operator

Question

Hi Miles,

I follow the instruction in following post and implement the autompo for 3spin operator successfully. Thanks a lot.
http://itensor.org/support/173/build-more-than-two-operator-terms-using-autompo

However, when I try to feed the mpo with 3 spin to auto expH = toExpH(ampo,tau*Cplx_i); It returns error. Is it because the implementation of toExpH for 3spin interaction is not yet complete? Are there simple workaround to get similar effect as toExpH for the 3spin MPO?

Thanks a lot.

Answer 1

Hi, so yes the answer is that toExpH still uses the older back end right now, which is the one that only supports up to two-site operators only. The newer back end that supports more than two is very complex, so it's not so straightforward to offer the toExpH feature without a lot of development and testing. I may be able to add it sometime over the next few months. Can you file a bug report about this on Github? (Not that it's a bug per se, but you can label it as a feature request.)

Miles