Move two_qubit_matrix_to_ion_operations to cirq/transformers/analyt…

…ical_decompositions (#5509)

Part of #2793

cirq-core/cirq/__init__.py

@@ -403,6 +403,7 @@
     transformer,
     two_qubit_matrix_to_cz_operations,
     two_qubit_matrix_to_diagonal_and_cz_operations,
+    two_qubit_matrix_to_ion_operations,
     two_qubit_matrix_to_sqrt_iswap_operations,
     two_qubit_gate_product_tabulation,
     TwoQubitCompilationTargetGateset,
@@ -669,7 +670,7 @@
     with_rescoped_keys,
 )
 
-from cirq.ion import ConvertToIonGates, IonDevice, two_qubit_matrix_to_ion_operations
+from cirq.ion import ConvertToIonGates, IonDevice
 from cirq.neutral_atoms import (
     ConvertToNeutralAtomGates,
     is_native_neutral_atom_gate,

cirq-core/cirq/ion/__init__.py

@@ -16,13 +16,7 @@
 
 from cirq.ops import ms
 
-from cirq.ion.ion_decomposition import two_qubit_matrix_to_ion_operations
-
-from cirq.ion.ion_device import IonDevice
-
-from cirq.ion.convert_to_ion_gates import ConvertToIonGates
-
-from cirq.ion.ion_decomposition import two_qubit_matrix_to_ion_operations
+from cirq.transformers import two_qubit_matrix_to_ion_operations
 
 from cirq.ion.ion_device import IonDevice
 

cirq-core/cirq/transformers/__init__.py

@@ -33,6 +33,7 @@
     three_qubit_matrix_to_operations,
     two_qubit_matrix_to_cz_operations,
     two_qubit_matrix_to_diagonal_and_cz_operations,
+    two_qubit_matrix_to_ion_operations,
     two_qubit_matrix_to_sqrt_iswap_operations,
 )
 

cirq-core/cirq/transformers/analytical_decompositions/__init__.py

@@ -50,6 +50,10 @@
     decompose_two_qubit_interaction_into_four_fsim_gates,
 )
 
+from cirq.transformers.analytical_decompositions.two_qubit_to_ms import (
+    two_qubit_matrix_to_ion_operations,
+)
+
 from cirq.transformers.analytical_decompositions.two_qubit_to_sqrt_iswap import (
     parameterized_2q_op_to_sqrt_iswap_operations,
     two_qubit_matrix_to_sqrt_iswap_operations,

cirq-core/cirq/ion/ion_decomposition.py → cirq-core/cirq/transformers/analytical_decompositions/two_qubit_to_ms.py

@@ -23,38 +23,46 @@
 
 import numpy as np
 
-from cirq import ops, linalg, protocols, circuits, transformers
-from cirq.ion import ms
+from cirq import ops, linalg, protocols, circuits
+from cirq.transformers.analytical_decompositions import single_qubit_decompositions
+from cirq.transformers.merge_single_qubit_gates import merge_single_qubit_gates_to_phased_x_and_z
+from cirq.transformers.eject_z import eject_z
+from cirq.transformers.eject_phased_paulis import eject_phased_paulis
 
 if TYPE_CHECKING:
     import cirq
 
 
 def two_qubit_matrix_to_ion_operations(
-    q0: 'cirq.Qid', q1: 'cirq.Qid', mat: np.ndarray, atol: float = 1e-8
+    q0: 'cirq.Qid',
+    q1: 'cirq.Qid',
+    mat: np.ndarray,
+    atol: float = 1e-8,
+    clean_operations: bool = True,
 ) -> List[ops.Operation]:
     """Decomposes a two-qubit operation into MS/single-qubit rotation gates.
 
     Args:
         q0: The first qubit being operated on.
         q1: The other qubit being operated on.
         mat: Defines the operation to apply to the pair of qubits.
-        atol: A limit on the amount of error introduced by the
-            construction.
+        atol: A limit on the amount of error introduced by the construction.
+        clean_operations: Enables optimizing resulting operation list by
+            merging operations and ejecting phased Paulis and Z operations.
 
     Returns:
         A list of operations implementing the matrix.
     """
     kak = linalg.kak_decomposition(mat, atol=atol)
     operations = _kak_decomposition_to_operations(q0, q1, kak, atol)
-    return _cleanup_operations(operations)
+    return _cleanup_operations(operations) if clean_operations else operations
 
 
-def _cleanup_operations(operations: List[ops.Operation]):
+def _cleanup_operations(operations: List[ops.Operation]) -> List['cirq.Operation']:
     circuit = circuits.Circuit(operations)
-    circuit = transformers.merge_single_qubit_gates_to_phased_x_and_z(circuit)
-    circuit = transformers.eject_phased_paulis(circuit)
-    circuit = transformers.eject_z(circuit)
+    circuit = merge_single_qubit_gates_to_phased_x_and_z(circuit)
+    circuit = eject_phased_paulis(circuit)
+    circuit = eject_z(circuit)
     circuit = circuits.Circuit(circuit.all_operations(), strategy=circuits.InsertStrategy.EARLIEST)
     return list(circuit.all_operations())
 
@@ -79,7 +87,7 @@ def _kak_decomposition_to_operations(
 
 
 def _do_single_on(u: np.ndarray, q: 'cirq.Qid', atol: float = 1e-8):
-    for gate in transformers.single_qubit_matrix_to_gates(u, atol):
+    for gate in single_qubit_decompositions.single_qubit_matrix_to_gates(u, atol):
         yield gate(q)
 
 
@@ -95,7 +103,7 @@ def _parity_interaction(
         g = cast(ops.Gate, gate)
         yield g.on(q0), g.on(q1)
 
-    yield ms(-1 * rads).on(q0, q1)
+    yield ops.ms(-1 * rads).on(q0, q1)
 
     if gate is not None:
         g = protocols.inverse(gate)

cirq-core/cirq/ion/ion_decomposition_test.py → cirq-core/cirq/transformers/analytical_decompositions/two_qubit_to_ms_test.py

@@ -1,4 +1,17 @@
-# pylint: disable=wrong-or-nonexistent-copyright-notice
+# Copyright 2018 The Cirq Developers
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import random
 
 import numpy as np