nelimee
commented
2 months ago I agree that this would be a very sensible and interesting addition. It might be too soon though. In my opinion, here are the steps we should focus on right now:
- Have a fully working logical CNOT computation. This has been our main goal since the beginning, we are very close now, so we should prioritize as much as possible that goal.
- Clean up the code, removing/simplifying/refactoring everything to have a clean code base that can still output a fully functional CNOT. This includes (non-exhaustive):
Templaterefactoring,- A huge documentation and testing improvement,
- Removing now useless code,
- Implement new features with the stabilized and cleaned-up code base.
I think this feature is 1) not needed for the completion of our first goal and 2) can wait until we finished cleaning up the codebase. An argument for implementing that now (instead of waiting) is that this feature is, at its core, "just" a translator from LaSre to BlockGraph, which only requires the API to create a BlockGraph instance (i.e., a small portion of the API) and so might not be impacted too much by a refactor.
Any opinion?
inmzhang
afowler
Is your feature request related to a problem? Please describe.
What is
LaSsynth?LaSsynthis a synthesis for lattice surgery subroutines. After specifying the desired inputs/outputs ports and the stabilizer flows, it will use a SAT solver to solve the internal structure of the lattice surgery construction under limited spacetime volume. You can take a look at this demo to learn more about it.Why is it useful for
tqec?LaSsynthprovides a way to automatically construct a valid spacetime model but can not run simulations for it. Then it's natural to take the output ofLaSsynthas the input oftqecto run and verify the construction at the circuit level.LaSsynthprovides a text format representation(LaSre) of the spacetime model and it can be taken as a starting point for the design of a portable text format oftqeccomputation structure.LaSsynthprovides the functionality to convert aLaSrefile to a.gltfmodel and visualized the model as well as the correlation surfaces.LaSsynthprovides the functionality to convert aLaSrefile to the corresponding zx diagrams(usingstimzx) representation and verify the the stabilizer flows.How it can be used with
tqec?LaSsynthprovides a representation of the Lattice Surgery subroutine in a text format calledLaSre.LaSre of CNOT
It can be seen as a complete description of the structure of a 3D spacetime model or our
BlockGraph. To be more specific:n_i/j/ks specify the the spacetime volumen_p/ports/port_cubesspecify the number and positions of inputs/outputs of the subroutine. And these ports can corresponds to the virtual cubes in theBlockGraph.n_s/stabsspecifies the stabilizer flow generators. The concept of the stabilizer flow translates naturally to the correlation surface in the lattice surgery model. And it relates to the existing correlation subgraphs inBlockGraph.ExistI/J/Kspecifies the positions of block structures including the cubes and pipes.ColorI/Jspecifies the type of the block structures.CorrIJ...specifies the explicit correlation surfaces presented in each pipe for each stabilizer flows.NodeYspecifies the existence of the Y basis initialization/measurements, which currently is not implemented intqecbut is planned for sure.As above, the one-to-one translation between
LaSreandBlockGraphshould be possible.Limitations
To integrate the two libraries, there are some problems that we need to solve in my mind:
LaSynthis not allowed by default, but can be enabled with some changes to the code.tqec, or turn off the option for now.LaSreto represent theBlockGraph, we need to be able to fill the ports with actual cubes, which corresponds to logical initialization/measurements that instantiate a subroutine into a real computation.