[https://github.com/SnowflurrySDK/Snowflurry.jl/ Snowflurry] is an open-source quantum computing library developed in [[Julia]] by [https://anyonsys.com/ Anyon Systems] that allows you to build, simulate, and run quantum circuits. A related library called [https://github.com/SnowflurrySDK/SnowflurryPlots.jl/ SnowflurryPlots] allows you to visualize the simulation results in a bar chart. Useful to explore quantum computing, its features are described in the [https://snowflurrysdk.github.io/Snowflurry.jl/dev/index.html documentation] and the [https://github.com/SnowflurrySDK/Snowflurry.jl installation guide is available on the GitHub page]. Like the [[PennyLane/en|PennyLane]] library, Snowflurry can be used to run quantum circuits on the [[MonarQ/en|MonarQ]] quantum computer.
== Installation ==
The quantum computer simulator with [https://github.com/SnowflurrySDK/Snowflurry.jl Snowflurry] is available on all of our clusters. The [https://julialang.org/ Julia] programming language must be loaded before accessing Snowflurry.
[[File:Question.png|40px|link=https://explainshell.com/explain?cmd={{urlencode:{{{1}}} }}]]
{{#tag:syntaxhighlight|{{{prompt|[username@narval ~]$}}} {{{1}}}{{{result|}}}|lang={{{lang|bash}}}}}
{{Command|module load julia
|result=}}
The Julia programming interface is then called and the Snowflurry quantum library is loaded (in about 5-10 minutes) with the commands
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{{#tag:syntaxhighlight|{{{prompt|[username@narval ~]$}}} {{{1}}}{{{result|}}}|lang={{{lang|bash}}}}}
{{Command|julia
|result=julia> import Pkg
julia> Pkg.add(url="https://github.com/SnowflurrySDK/Snowflurry.jl", rev="main")
julia> Pkg.add(url="https://github.com/SnowflurrySDK/SnowflurryPlots.jl", rev="main")
julia> using Snowflurry}}
Quantum logic gates and commands are described in the [https://snowflurrysdk.github.io/Snowflurry.jl/dev/ Snowflurry documentation].
== Use case: Bell states ==
Bell states are maximally entangled two-qubit states. They are simple examples of two quantum phenomena: superposition and entanglement. The [https://github.com/SnowflurrySDK/Snowflurry.jl/ Snowflurry] library allows you to construct the first Bell state as follows:
{{Command|julia
|result=julia> using Snowflurry
julia> circuit=QuantumCircuit(qubit_count=2);
julia> push!(circuit,hadamard(1));
julia> push!(circuit,control_x(1,2));
julia> print(circuit)
Quantum Circuit Object:
qubit_count: 2
q[1]:──H────*──
¦
q[2]:───────X──
}}
In the above code section, the Hadamard gate creates an equal superposition of |0⟩ and |1⟩ on the first qubit while the CNOT gate (controlled X gate) creates an entanglement between the two qubits. We find an equal superposition of states |00⟩ and |11⟩, which is the first Bell state. The simulate function allows us to simulate the exact state of the system.
julia> state = simulate(circuit)
julia> print(state)
4-element Ket{ComplexF64}:
0.7071067811865475 + 0.0im
0.0 + 0.0im
0.0 + 0.0im
0.7071067811865475 + 0.0im
The readout operation lets you specify which qubits will be measured. The plot_histogram function from the SnowflurryPlots library allows you to visualize the results.
{{Command|julia
|result=julia> using SnowflurryPlots
julia> push!(circuit, readout(1,1), readout(2,2))
julia> plot_histogram(circuit,1000)
}}
[[File:Bell Graph.png|thumb|alt=Résultats de 1000 simulations de l'état de Bell.]]