Kyulacs.jl

Unofficial Julia interface for qulacs.

Prerequisites

1. Install Python and qulacs >= 0.5.1, qulacsvis >= 0.3.2 via

console $ pip3 install qulacs qulacsvis

1. Install Julia. If you're Julian, you can skip this step.

console $ pip3 install jill # A cross-platform installer for Pythonista $ jill install 1.8

After that you're supposed to add ${HOME}/.local/bin to your $PATH environment variable. You'll see the result below:

``console $ which julia $ ~/.local/bin/julia $ julia _ _ _ _(_)_ | Documentation: https://docs.julialang.org (_) | (_) (_) | _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help. | | | | | | |/ _ | | | | || | | | (| | | Version 1.8.3 (2022-11-14) / |_'|||_'| | Official https://julialang.org/ release |_/ |

julia> println("Hello") Hello

julia> exit() ```

1. Install PyCall

``conosle $ julia _ _ _ _(_)_ | Documentation: https://docs.julialang.org (_) | (_) (_) | _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help. | | | | | | |/ _ | | | | || | | | (| | | Version 1.8.3 (2022-11-14) / |_'|||_'| | Official https://julialang.org/ release |_/ |

julia> ENV["PYTHON"] = Sys.which("python3") julia> using Pkg; Pkg.add("PyCall") ```

Having trouble with the error messages ImportError: No module named site? Did you install Python via pyenv or asdf? Please re-install or install another Python again with CONFIGURE_OPTS="--enable-shared" option. Namely run one of the following:

$ CONFIGURE_OPTS="--enable-shared" pyenv 3.8.11 $ CONFIGURE_OPTS="--enable-shared" asdf install python 3.8.11

1. Install Kyulacs.jl

conosle $ git clone https://github.com/AtelierArith/Kyulacs.jl.git $ cd Kyulacs.jl $ julia --project=@. -e 'using Pkg; Pkg.instantiate()' $ julia --project=@. -e 'using Pkg; Pkg.test()'

How to use

Let's assume you've written a Python code which is similar to Python sample code given by qulacs.

```python

examples/readme_example.py

from qulacs import Observable, QuantumCircuit, QuantumState from qulacs.gate import Y, CNOT, merge

state = QuantumState(3) seed = 0 # set random seed state.setHaarrandom_state(seed)

circuit = QuantumCircuit(3) circuit.addXgate(0) mergedgate = merge(CNOT(0, 1), Y(1)) circuit.addgate(mergedgate) circuit.addRXgate(1, 0.5) circuit.updatequantum_state(state)

observable = Observable(3) observable.addoperator(2.0, "X 2 Y 1 Z 0") observable.addoperator(-3.0, "Z 2") value = observable.getexpectationvalue(state) print(value)

```

You can try this code out of the box even if you are not familiar with quantum computing.

conosle $ cd /path/to/this/repository $ julia --project=@. examples/readme_example.jl

In Julia, we can achieve the same functionality with Kyulacs package.

```julia:readmetestreadme_example.jl

examples/readme_example.jl

using Kyulacs: Observable, QuantumCircuit, QuantumState using Kyulacs.Gate: CNOT, Y, merge

state = QuantumState(3) seed = 0 # set random seed state.setHaarrandom_state(seed)

circuit = QuantumCircuit(3) circuit.addXgate(0) mergedgate = merge(CNOT(0, 1), Y(1)) circuit.addgate(mergedgate) circuit.addRXgate(1, 0.5) circuit.updatequantum_state(state)

observable = Observable(3) observable.addoperator(2.0, "X 2 Y 1 Z 0") observable.addoperator(-3.0, "Z 2") value = observable.getexpectationvalue(state) println(value) ```

Have a try!!!

console $ cd /path/to/this/repository $ julia -e "using InteractiveUtils; versioninfo()" Julia Version 1.7.2 Commit bf53498635 (2022-02-06 15:21 UTC) Platform Info: OS: macOS (x86_64-apple-darwin19.5.0) CPU: Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz WORD_SIZE: 64 LIBM: libopenlibm LLVM: libLLVM-12.0.1 (ORCJIT, skylake) $ julia --project=@. examples/readme_example.jl

These are pretty much the same thing. In fact, diff tells these are almost same.

```console $ diff readmeexample.py readmeexample.jl 1,3c1,3 < # readme_example.py < from qulacs import Observable, QuantumCircuit, QuantumState

< from qulacs.gate import Y, CNOT, merge

readme_example.jl

using Kyulacs: Observable, QuantumCircuit, QuantumState using Kyulacs.Gate: CNOT, Y, merge 21c21

< print(value)

println(value) ```

Code Design

When you want migrate your code from Python to Julia, the following table may help you:

Python | Julia ------------- | ------------- from qulacs import something | using Kyulacs: something from qulacs.circuit import something | using Kyulacs.Gate: something from qulacs.gate import something | using Kyulacs.Gate: something from qulacs.observable import something | using Kyulacs.ObservableFunctions: something from qulacs.quantum_operator import something | using Kyulacs.QuantumOperator: something from qulacs.state import something | using Kyulacs.State: something from qulacsvis.visualization import something | using Kyulacs.Vis: something

If you feel using Kyulacs.ObservableFunctions is too exaggerated. Please send your feedback/idea to our issue tracker.

GPU API

using Kyulacs.GPU will export StateVectorGpu and QuantumStateGpu that wraps qulacs.StateVectorGpu and qulacs.QuantumStateGpu respectively.

Visualization

Kyulacs.jl also supports qulacsvis integration. The statement using Kyulacs.Vis allows us to use Python API under qulacsvis.visualization. Consider the following Julia code:

```julia:readmetestcircuit_drawer.jl using Kyulacs: ParametricQuantumCircuit

exports circuit_drawer

using Kyulacs.Vis

nqubits = 2 circuit = ParametricQuantumCircuit(nqubits) circuit.addparametricRYgate(0, 0.0) circuit.addparametricRYgate(1, 0.0)

circuit.addparametricRYgate(0, 0.0) circuit.addCNOTgate(0, 1) circuit.addparametricRYgate(0, 0.0)

circuit_drawer(circuit) ```

We'll get:

```console

---

|pRY| |pRY| |pRY| --| |---| |-----●-----| |-- || || | |__| __ | |pRY| |CX | --| |-----------| |---------- || ||

```

Docker

• You can run Kyulacs.jl out of the box inside the official Julia Docker container:

``console $ docker run --rm -it julia:1.8.3 _ _ _ _(_)_ | Documentation: https://docs.julialang.org (_) | (_) (_) | _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help. | | | | | | |/ _ | | | | || | | | (| | | Version 1.8.3 (2022-11-14) / |_'|||_'| | Official https://julialang.org/ release |_/ |

julia> using Pkg julia> pkg"registry add General https://github.com/AtelierArith/Gallery.git" julia> Pkg.add("Conda") # Install Conda.jl julia> using Conda julia> Conda.pipinterop(true) julia> Conda.pip("install", "qulacs") julia> Conda.pip("install", "qulacsvis") julia> using Kyulacs: Observable, QuantumCircuit, QuantumState julia> using Kyulacs.Gate: CNOT, Y, merge julia> state = QuantumState(3) julia> seed = 0 # set random seed julia> state.setHaarrandomstate(seed) julia> circuit = QuantumCircuit(3) julia> circuit.addXgate(0) julia> mergedgate = merge(CNOT(0, 1), Y(1)) julia> circuit.addgate(mergedgate) julia> circuit.addRXgate(1, 0.5) julia> circuit.updatequantumstate(state) julia> observable = Observable(3) julia> observable.addoperator(2.0, "X 2 Y 1 Z 0") julia> observable.addoperator(-3.0, "Z 2") julia> value = observable.getexpectation_value(state) ```

Appendix

Docker

console $ git clone https://github.com/AtelierArith/Kyulacs.jl.git $ cd Kyulacs.jl $ make && make test $ make build-gpu && make test-gpu # for gpu version

Blog post

• Zenn: (Japanese blog post)
• Qiita: (Japanese blog post)

Sponsorship

If you want to see more of our work, consider sponsoring us via Github sponsors.