Updating GST to accept parameterised gates

doc/source/code-examples/advancedexamples.rst

@@ -2242,7 +2242,8 @@ Let's first define the set of gates we want to estimate:
 
    from qibo import gates
 
-   gate_set = {gates.X, gates.H, gates.CZ}
+   target_gates = [gates.RX(0, np.pi/3), gates.Z(0), gates.PRX(0, np.pi/2, np.pi/3), gates.GPI(0, np.pi/7), gates.CNOT(0,1)]
+   gate_set = [(g.__class__, [g.parameters[i] for i in range(len(g.parameters))]) if g.parameters else (g.__class__, []) for g in target_gates]
 
 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

@@ -1,13 +1,14 @@
 from functools import cache
 from inspect import signature
 from itertools import product
+from random import Random
 from typing import List, Union
 
 import numpy as np
 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
@@ -227,7 +228,12 @@ def GST(
     """Runs 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. target_gates = [gates.RX(0, np.pi/3), gates.Z(0), gates.PRX(0, np.pi/2, np.pi/3),
+                                 gates.GPI(0, np.pi/7), gates.CNOT(0,1)]
+                 gate_set = [(g.__class__, [g.parameters[i] for i in range(len(g.parameters))])
+                             if g.parameters else (g.__class__, []) for g in target_gates]
         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 +266,15 @@ 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 = []
@@ -278,7 +292,15 @@ def GST(
 
     for gate in gate_set:
         if gate is not None:
-            init_args = signature(gate).parameters
+            init_args = signature(gate[0]).parameters
+            params = gate[1]
+
+            angle_names = [name for name in init_args if name in {"theta", "phi"}]
+
+            angle_values = {}
+            for name, value in zip(angle_names, params):  # Zip ensures correct order
+                angle_values[name] = value
+
             if "q" in init_args:
                 nqubits = 1
             elif "q0" in init_args and "q1" in init_args and "q2" not in init_args:
@@ -288,7 +310,7 @@ def GST(
                     RuntimeError,
                     f"Gate {gate} is not supported for `GST`, only 1- and 2-qubits gates are supported.",
                 )
-            gate = gate(*range(nqubits))
+            gate = gate[0](*range(nqubits), **angle_values)
 
         matrices.append(
             _gate_tomography(

tests/test_tomography_gate_set_tomography.py

@@ -204,7 +204,10 @@ 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.Z(0), 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):
@@ -215,9 +218,16 @@ 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]
+    gate_set = [
+        (
+            (g.__class__, [g.parameters[i] for i in range(len(g.parameters))])
+            if g.parameters
+            else (g.__class__, [])
+        )
+        for g in target_gates
+    ]
 
-    if len(target_gates) == 3:
+    if len(target_gates) == 4:
         empty_1q, empty_2q, *approx_gates = GST(
             gate_set=gate_set,
             nshots=int(1e4),
@@ -241,7 +251,7 @@ 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 +275,14 @@ 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__, [g.parameters[i] for i in range(len(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,