Convert Qibo circuits to Quantum Tensor Networks (#214)

* Add qibo dependency

* Add module for Qibo circuit to Tenet conversion

* Add Qibo.jl module

* Add Qibo-Tenet conversion test

* Format code

* Fix qibo import name

* Set numpy as qibo backend

CondaPkg.toml

@@ -1,4 +1,5 @@
 [deps]
+qibo = ""
 qiskit = ""
 
 [pip.deps]

ext/TenetPythonCallExt/Qibo.jl

@@ -0,0 +1,40 @@
+function Tenet.Quantum(::Val{:qibo}, pyobj::Py)
+    qibo = pyimport("qibo")
+    qibo.set_backend("numpy")
+    if !pyissubclass(pytype(pyobj), qibo.models.circuit.Circuit)
+        throw(ArgumentError("Expected a qibo.models.circuit.Circuit object, got $(pyfullyqualname(pyobj))"))
+    end
+
+    n = pyconvert(Int, pyobj.nqubits)
+    gen = Tenet.IndexCounter()
+
+    wire = [[Tenet.nextindex!(gen)] for _ in 1:n]
+    tn = TensorNetwork()
+    circgates = pyobj.queue
+
+    for gate in circgates
+        matrix = pyconvert(Array, gate.matrix())
+
+        qubits = map(x -> pyconvert(Int, x), gate.qubits)
+        array = reshape(matrix, fill(2, 2 * length(qubits))...)
+
+        inds = (x -> collect(Iterators.flatten(zip(x...))))(
+            map(qubits) do l
+                l += 1
+                from, to = last(wire[l]), Tenet.nextindex!(gen)
+                push!(wire[l], to)
+                (from, to)
+            end,
+        )
+
+        tensor = Tensor(array, Tuple(inds))
+        push!(tn, tensor)
+    end
+
+    sites = merge(
+        Dict([Site(site; dual=true) => first(index) for (site, index) in enumerate(wire) if first(index) ∈ tn]),
+        Dict([Site(site; dual=false) => last(index) for (site, index) in enumerate(wire) if last(index) ∈ tn]),
+    )
+
+    return Quantum(tn, sites)
+end

ext/TenetPythonCallExt/TenetPythonCallExt.jl

@@ -18,5 +18,6 @@ end
 
 include("Qiskit.jl")
 include("Quimb.jl")
+include("Qibo.jl")
 
 end

test/integration/python/test_qibo.jl

@@ -0,0 +1,18 @@
+@testset "qibo" begin
+    using PythonCall
+    qibo = pyimport("qibo")
+
+    circuit = qibo.Circuit(3)
+    circuit.add(qibo.gates.H(0))
+    circuit.add(qibo.gates.H(1))
+    circuit.add(qibo.gates.CNOT(1, 2))
+    circuit.add(qibo.gates.CNOT(0, 2))
+    circuit.add(qibo.gates.H(0))
+    circuit.add(qibo.gates.H(1))
+    circuit.add(qibo.gates.H(2))
+
+    tn = Tenet.Quantum(circuit)
+    @test issetequal(sites(tn; set=:inputs), adjoint.(Site.([1, 2, 3])))
+    @test issetequal(sites(tn; set=:outputs), Site.([1, 2, 3]))
+    @test Tenet.ntensors(tn) == 7
+end

test/runtests.jl

@@ -29,6 +29,7 @@ if VERSION >= v"1.10"
         @testset "Python" begin
             include("integration/python/test_quimb.jl")
             include("integration/python/test_qiskit.jl")
+            include("integration/python/test_qibo.jl")
         end
     end
 end