FLOYao.jl

A Yao.jl backend to efficiently simulated fermionic linear optics (FLO) circuits in based on Classical simulation of noninteracting-fermion quantum circuits and Disorder-assisted error correction in Majorana chains. FLO circuits are a class of quantum circuits that are closely related to non-interacting fermions and can be efficiently simulated on classical computers, similar to the way Clifford circuits can be efficiently classically simulated, as is done in YaoClifford.jl.

The goal of FLOYao is that if you have code written in Yao.jl that only uses FLO gates and other primitives that are efficiently simulatable in polynomial time and space, that you can simply replace your AbstractArrayReg with a MajoranaReg and run exactly the same simulation, with the same code but exponentially faster.

A brief introduction to fermionic linear optics circuits is found in the Documentation and a more in-depth introduction in e.g. the two papers linked above.

FLOYao can be simply installed from the REPL via

pkg> add FLOYao

First import FLOYao and Yao

using FLOYao, Yao

then build a (here somewhat arbitrary) circuit consisting only of Supported gates

nq = 4
θ = π/8
circuit = chain(nq)

push!(circuit, put(nq, 3=>Rz(0.5)))

xxg1 = kron(nq, 1 => X, 2 => X)
rg = rot(xxg1, θ)
push!(circuit, rg)  

xxg2 = kron(nq, 2 => X, 3 => Z, 4 => X)
rg = rot(xxg2, θ)
push!(circuit, rg)  
push!(circuit, put(nq, 3=>Rz(0.5)))
push!(circuit, put(nq, 1=>Z))

xxg3 = kron(nq, 2 => X, 3 => X)
rg = rot(xxg3, θ)
push!(circuit, rg)

and create a FLO state, pipe it through the circuit and measure the result

FLOYao.zero_state(nq) |> circuit |> measure!

The documentation for the last release is here and the documentation for the current development branch here.