Updating GST to accept parameterised gates

doc/source/code-examples/advancedexamples.rst

@@ -2242,7 +2242,7 @@ Let's first define the set of gates we want to estimate:
 
    from qibo import gates
 
-   gate_set = {gates.X, gates.H, gates.CZ}
+   gate_set = [(gates.RX, [np.pi/3]), gates.Z, (gates.PRX, [np.pi/2, np.pi/3]), (gates.GPI, [np.pi/7]), gates.CNOT]
 
 For simulation purposes we can define a noise model. Naturally this is not needed when running on real quantum hardware, which is intrinsically noisy. For example, we can suppose that the three gates we want to estimate are going to be noisy:
 

src/qibo/tomography/gate_set_tomography.py

@@ -7,7 +7,7 @@
 from sympy import S
 
 from qibo import Circuit, gates, symbols
-from qibo.backends import _check_backend, get_transpiler
+from qibo.backends import _check_backend
 from qibo.config import raise_error
 from qibo.hamiltonians import SymbolicHamiltonian
 from qibo.transpiler.optimizer import Preprocessing
@@ -224,10 +224,13 @@ def GST(
     backend=None,
     transpiler=None,
 ):
-    """Runs Gate Set Tomography on the input ``gate_set``.
+    """Run Gate Set Tomography on the input ``gate_set``.
 
     Args:
-        gate_set (tuple or set or list): set of :class:`qibo.gates.Gate` to run GST on.
+        gate_set (tuple or set or list): set of :class:`qibo.gates.Gate` and parameters to run
+            GST on.
+            E.g. gate_set = [(gates.RX, [np.pi/3]), gates.Z, (gates.PRX, [np.pi/2, np.pi/3]),
+                             (gates.GPI, [np.pi/7]), gates.CNOT]
         nshots (int, optional): number of shots used in Gate Set Tomography per gate.
             Defaults to :math:`10^{4}`.
         noise_model (:class:`qibo.noise.NoiseModel`, optional): noise model applied to simulate
@@ -260,7 +263,15 @@ def GST(
     backend = _check_backend(backend)
 
     if backend.name == "qibolab" and transpiler is None:  # pragma: no cover
-        transpiler = get_transpiler()
+        transpiler = Passes(
+            connectivity=backend.platform.topology,
+            passes=[
+                Preprocessing(backend.platform.topology),
+                Random(backend.platform.topology),
+                Sabre(backend.platform.topology),
+                Unroller(NativeGates.default()),
+            ],
+        )
 
     matrices = []
     empty_matrices = []
@@ -278,17 +289,27 @@ def GST(
 
     for gate in gate_set:
         if gate is not None:
-            init_args = signature(gate).parameters
+
+            if isinstance(gate, tuple):
+                angles = ["theta", "phi", "lam"]
+                gate, params = gate
+                init_args = signature(gate).parameters
+                valid_angles = [arg for arg in init_args if arg in angles]
+                angle_values = dict(zip(valid_angles, params))
+            else:
+                angle_values = {}
+                init_args = signature(gate).parameters
+
             if "q" in init_args:
                 nqubits = 1
             elif "q0" in init_args and "q1" in init_args and "q2" not in init_args:
                 nqubits = 2
             else:
                 raise_error(
                     RuntimeError,
-                    f"Gate {gate} is not supported for `GST`, only 1- and 2-qubits gates are supported.",
+                    f"Gate {gate} is not supported for `GST`, only 1- and 2-qubit gates are supported.",
                 )
-            gate = gate(*range(nqubits))
+            gate = gate(*range(nqubits), **angle_values)
 
         matrices.append(
             _gate_tomography(

tests/test_tomography_gate_set_tomography.py

@@ -204,7 +204,15 @@ def test_gate_tomography_noise_model(backend):
 
 @pytest.mark.parametrize(
     "target_gates",
-    [[gates.SX(0), gates.Z(0), gates.CY(0, 1)], [gates.TOFFOLI(0, 1, 2)]],
+    [
+        [
+            gates.SX(0),
+            gates.RX(0, np.pi / 4),
+            gates.PRX(0, np.pi, np.pi / 2),
+            gates.CY(0, 1),
+        ],
+        [gates.TOFFOLI(0, 1, 2)],
+    ],
 )
 @pytest.mark.parametrize("pauli_liouville", [False, True])
 def test_GST(backend, target_gates, pauli_liouville):
@@ -215,17 +223,20 @@ def test_GST(backend, target_gates, pauli_liouville):
     target_matrices = [
         to_pauli_liouville(m, normalize=True, backend=backend) for m in target_matrices
     ]
-    gate_set = [g.__class__ for g in target_gates]
 
-    if len(target_gates) == 3:
+    gate_set = [
+        ((g.__class__, list(g.parameters)) if g.parameters else g.__class__)
+        for g in target_gates
+    ]
+
+    if len(target_gates) == 4:
         empty_1q, empty_2q, *approx_gates = GST(
             gate_set=gate_set,
             nshots=int(1e4),
             include_empty=True,
             pauli_liouville=pauli_liouville,
             backend=backend,
         )
-        print(type(empty_1q), type(empty_2q))
         T_2q = np.kron(T, T)
         for target, estimate in zip(target_matrices, approx_gates):
             if not pauli_liouville:
@@ -241,7 +252,7 @@ def test_GST(backend, target_gates, pauli_liouville):
     else:
         with pytest.raises(RuntimeError):
             empty_1q, empty_2q, *approx_gates = GST(
-                gate_set=[g.__class__ for g in target_gates],
+                gate_set=gate_set,
                 nshots=int(1e4),
                 include_empty=True,
                 pauli_liouville=pauli_liouville,
@@ -265,7 +276,10 @@ def test_GST_with_transpiler(backend, star_connectivity):
     import networkx as nx
 
     target_gates = [gates.SX(0), gates.Z(0), gates.CNOT(0, 1)]
-    gate_set = [g.__class__ for g in target_gates]
+    gate_set = [
+        ((g.__class__, list(g.parameters)) if g.parameters else g.__class__)
+        for g in target_gates
+    ]
     # standard not transpiled GST
     empty_1q, empty_2q, *approx_gates = GST(
         gate_set=gate_set,