Compress MPS with given maximal bond dimension

ITensor Julia Questions
1

Hi,

I am wondering if there is an equivalent operation in julia to this. Basically, is there a short-hand function for compressing MPS with a given bond dimension and cutoff?

Thanks,
Z

2

Hi Zhen,
I think the function you are looking for is the truncate(psi; kws...) function. So like you can do:

cutoff=1E-8
psi = truncate(psi; cutoff)

and similar, with the usual truncation parameters (cutoff, maxdim, mindim).

Also there is the orthogonalize function which shifts the orthogonality ‘center’ site but does not truncate.

3

Truncate docs:https://docs.itensor.org/ITensorMPS/stable/MPSandMPO.html#NDTensors.truncate!

Orthogonalize docs: https://docs.itensor.org/ITensorMPS/stable/MPSandMPO.html#ITensorMPS.orthogonalize!

4

Thanks!

Zhen