Quac

Quac stands for Quantum circuits and its a Julia library for quantum circuits with no assumptions about their use.

What does this means, you ask? Well, Quac is not a simulator, neither a controller of quantum computers. It just provides a Circuit data stracture, a set of gates and tools to manipulate them. Developers may use it as the core of their simulators or hardware controllers.

⚠️ Measurement gates are not currently supported as we are exploring how to fit non-unitary gates.

Features

Multiple representation of gates

Gates are symbolic in the sense that they do not store their representation. In Quac a gate just stores the lane in which it acts, and parameters if it's a parametric gate. Thanks to Julia's multiple-dispatch different representations can be queried lazily.

For example, this is a $Z$ that acts on qubit 4.

julia> using Quac
julia> gate = Z(4)

Any gate can be represented by a dense matrix.

julia> Matrix(gate)
2×2 Matrix{ComplexF32}:
 1.0+0.0im   0.0+0.0im
 0.0+0.0im  -1.0+0.0im

You can even specify the eltype!

julia> Matrix{Int}(gate)
2×2 Matrix{Int64}:
 1   0
 0  -1

Furthermore, the $Z$ gate allows a Diagonal representation!

julia> using LinearAlgebra
julia> Diagonal{Float32}(gate)
2×2 Diagonal{Float32, Vector{Float32}}:
 1.0    ⋅
  ⋅   -1.0

Layout-agnostic Circuit representation

Quac uses multi-priority queues for representing Circuits.

SVG rendering of Circuits

using Quac

circ = Quac.Algorithms.QFT(4)
draw(circ)

Roadmap

• Gate decompositions
• ZX-calculus
• Spatial layouts
• Measurements
• Visualization
• Support for qudits