Merge pull request #219 from GTorlai/multi-qubit-gates

fixed n-qubit gates (n>2)

Project.toml

@@ -1,7 +1,7 @@
 name = "PastaQ"
 uuid = "30b07047-aa8b-4c78-a4e8-24d720215c19"
 authors = ["Giacomo Torlai <[email protected]>", "Matthew Fishman <[email protected]>"]
-version = "0.0.8"
+version = "0.0.9"
 
 [deps]
 HDF5 = "f67ccb44-e63f-5c2f-98bd-6dc0ccc4ba2f"

src/circuits/gates.jl

@@ -513,14 +513,8 @@ acting on sites `(site[1],site[2])`, with indices identical to a
 reference state `M` (`MPS` or `MPO`).
 """
 function gate(M::Union{MPS,MPO}, gatename::String, site::Tuple; kwargs...)
-  site_ind1 = (
-    typeof(M) == MPS ? siteind(M, site[1]) : firstind(M[site[1]]; tags="Site", plev=0)
-  )
-  site_ind2 = (
-    typeof(M) == MPS ? siteind(M, site[2]) : firstind(M[site[2]]; tags="Site", plev=0)
-  )
-
-  return gate(gatename, site_ind1, site_ind2; kwargs...)
+  site_inds = [typeof(M) == MPS ? siteind(M, s) : firstind(M[s]; tags="Site", plev=0) for s in site]
+  return gate(gatename, site_inds...; kwargs...)
 end
 
 gate(M::Union{MPS,MPO}, gatedata::Tuple) = gate(M, gatedata...)

test/runcircuit.jl

@@ -104,6 +104,25 @@ end
   @test prod(ρ) ≈ runcircuit(prod(ρ0), buildcircuit(ρ0, gates); apply_dag=true)
 end
 
+
+@testset "runcircuit: (n>2)-qubit gates" begin
+  N = 3
+  depth = 4
+  gates = randomcircuit(N, depth; layered=false)
+  push!(gates, ("Toffoli",(1,2,3)))
+  #Pure state, noiseless circuit
+  ψ0 = productstate(N)
+  ψ = runcircuit(ψ0, gates)
+  @test prod(ψ) ≈ runcircuit(prod(ψ0), buildcircuit(ψ0, gates))
+  @test PastaQ.array(prod(ψ)) ≈ PastaQ.array(prod(runcircuit(N, gates)))
+  @test PastaQ.array(prod(ψ)) ≈ PastaQ.array(prod(runcircuit(gates)))
+
+  # Mixed state, noiseless circuit
+  ρ0 = MPO(productstate(N))
+  ρ = runcircuit(ρ0, gates)
+  @test prod(ρ) ≈ runcircuit(prod(ρ0), buildcircuit(ρ0, gates); apply_dag=true)
+end
+
 @testset "runcircuit: noisy quantum circuit" begin
   N = 5
   depth = 4