+1 vote
asked by (230 points)

Hey all,
If I want to constuct a wave function that has a superposition of MPS, is it posible ? do I need to normalize it ?
For example:
psi= 1/sqrt(2) * MPS(s,"Up") + 1/sqrt(2) * MPS(s,"Dn")
hope for a reply soon =)

1 Answer

0 votes
answered by (70.1k points)

Hi, yes you can add two MPS together as you have written. Here is some more technical documentation on addition of MPS in ITensor: https://itensor.github.io/ITensors.jl/stable/MPSandMPO.html#Base.:+-Tuple{MPS,%20MPS}

Regarding the question of normalization, it is really your choice. If you wish the result to be normalized, you will need to normalize it. You can do this by putting factors in the sum as you have done, or normalizing the result afterward. If you do not want the resulting MPS to be normalized, then you can leave the factors out of the sum.

Best regards,

Welcome to ITensor Support Q&A, where you can ask questions and receive answers from other members of the community.

Formatting Tips:
  • To format code, indent by four spaces
  • To format inline LaTeX, surround it by @@ on both sides
  • To format LaTeX on its own line, surround it by $$ above and below
  • For LaTeX, it may be necessary to backslash-escape underscore characters to obtain proper formatting. So for example writing \sum\_i to represent a sum over i.
If you cannot register due to firewall issues (e.g. you cannot see the capcha box) please email Miles Stoudenmire to ask for an account.

To report ITensor bugs, please use the issue tracker.