QXTns is a Julia package with data structures and utilities for manipulating tensor networks. As well as generic tensor network data structure, it also contains specific data structures for handling tensor networks derived from quantum circuits. It was developed as part of the QuantEx project, one of the individual software projects of WP8 of PRACE 6IP.
It uses some features from ITensors and NDTensors for representing tensors and indices and performing contractions.
QXTns is a Julia package and can be installed using Julia's inbuilt package manager from the Julia REPL using.
import Pkg
Pkg.add("QXTns")
To ensure everything is working, the unittests can be run using
import Pkg; Pkg.test()
An example of creating a simple tensor network and contracting.
using QXTns
tn = TensorNetwork()
a, b, c, d = Index(2), Index(3), Index(5), Index(4)
# add a 2x3x5 rank tensor
push!(tn, [a, b, c], rand(2, 3, 5))
# add a 5x4 matrix
push!(tn, [c, d], rand(5, 4))
# contract network
simple_contraction!(tn)
# number of tensors after contraction
@show length(tn)
# resulting tensor has dimensions should have dimensions 2x3x4
@show size(first(tn))
Contributions from users are welcome and we encourage users to open issues and submit merge/pull requests for any problems or feature requests they have. The CONTRIBUTING.md has further details of the contribution guidelines.
QXTns.jl uses Documenter.jl to generate documentation. To build the documentation locally run the following from the root folder.
The first time it is will be necessary to instantiate the environment to install dependencies
julia --project=docs/ -e 'using Pkg; Pkg.develop(PackageSpec(path=pwd())); Pkg.instantiate()'
and then to build the documentation
julia --project=docs/ docs/make.jl
The generated document will be in the docs/build folder. To serve these locally one can
use the LiveServer package as
julia --project -e 'import Pkg; Pkg.add("LiveServer");
julia --project -e 'using LiveServer; serve(dir="docs/build")'
Or with python3 using from the docs/build folder using
python3 -m http.server
The generated documentation should now be viewable locally in a browser at http://localhost:8000.