Add pasqal device

pennylane_cirq/__init__.py

@@ -16,6 +16,7 @@
 ===============
 """
 from .simulator_device import SimulatorDevice, MixedStateSimulatorDevice
+from .pasqal_device import PasqalDevice
 
 from .ops import BitFlip, PhaseFlip, PhaseDamp, AmplitudeDamp, Depolarize
 from ._version import __version__

pennylane_cirq/cirq_device.py

@@ -46,7 +46,7 @@ class CirqDevice(QubitDevice, abc.ABC):
     """Abstract base device for PennyLane-Cirq.
 
     Args:
-        wires (int): the number of modes to initialize the device in
+        wires (int): the number of wires to initialize the device with
         shots (int): Number of circuit evaluations/random samples used
             to estimate expectation values of observables. Shots need to be >= 1.
         qubits (List[cirq.Qubit]): a list of Cirq qubits that are used

pennylane_cirq/pasqal_device.py

@@ -0,0 +1,52 @@
+# Copyright 2018 Xanadu Quantum Technologies Inc.
+
+# 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
+
+#     http://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.
+# pylint: disable=too-many-arguments
+"""
+This module provides the ``PasqalDevice`` from Cirq.
+"""
+from cirq import pasqal
+
+from .simulator_device import SimulatorDevice
+
+
+class PasqalDevice(SimulatorDevice):
+    r"""Cirq Pasqal device for PennyLane.
+
+    Args:
+        wires (int): the number of wires to initialize the device with
+        shots (int): Number of circuit evaluations/random samples used
+            to estimate expectation values of observables. Shots need
+            to be >= 1. In analytic mode, shots indicates the number of entries
+            that are returned by ``device.sample``.
+        analytic (bool): Indicates whether expectation values and variances should
+            be calculated analytically. Defaults to ``True``.
+        qubits (List[cirq.ThreeDGridQubit]): A list of Cirq ThreeDGridQubits that are used
+            as wires. If not specified, the ThreeDGridQubits are put in a linear
+            arrangement along the first coordinate axis,
+            i.e., (0,0,0), (1,0,0), (2,0,0), etc.
+        control_radius (float): The maximum distance between qubits for a controlled
+                gate. Distance is measured in units of the indices passed into
+                the qubits keyword argument.
+    """
+    name = "Cirq Pasqal device for PennyLane"
+    short_name = "cirq.pasqal"
+
+    def __init__(self, wires, shots=1000, analytic=True, qubits=None, control_radius=1.0):
+
+        if not qubits:
+            qubits = [pasqal.ThreeDGridQubit(wire, 0, 0) for wire in range(wires)]
+        self.control_radius = float(control_radius)
+        if self.control_radius < 0:
+            raise ValueError("The control_radius must be a non-negative real number.")
+        super().__init__(wires, shots, analytic, qubits)

requirements.txt

@@ -1,3 +1,4 @@
 pennylane>=0.9
-cirq>=0.7
+google-api-core[grpc]<=1.14.0
+git+https://github.com/lhenriet/Cirq.git
 numpy~=1.16

setup.py

@@ -35,7 +35,8 @@
     "license": "Apache License 2.0",
     "packages": ["pennylane_cirq"],
     "entry_points": {"pennylane.plugins": ["cirq.simulator = pennylane_cirq:SimulatorDevice",
-                                           "cirq.mixedsimulator = pennylane_cirq:MixedStateSimulatorDevice"],},
+                                           "cirq.mixedsimulator = pennylane_cirq:MixedStateSimulatorDevice",
+                                           "cirq.pasqal = pennylane_cirq:PasqalDevice"],},
     # Place a one line description here. This will be shown by pip
     "description": "PennyLane plugin for Cirq",
     "long_description": open("README.rst").read(),

tests/test_pasqal_device.py

@@ -0,0 +1,80 @@
+# Copyright 2018 Xanadu Quantum Technologies Inc.
+
+# 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
+
+#     http://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.
+"""
+Unit tests for the PasqalDevice
+"""
+import pytest
+
+import pennylane as qml
+from pennylane_cirq import PasqalDevice, SimulatorDevice
+from cirq.pasqal import ThreeDGridQubit
+
+
+class TestDeviceIntegration:
+    """Tests that the SimulatorDevice integrates well with PennyLane"""
+
+    def test_device_loading(self):
+        """Tests that the cirq.pasqal device is properly loaded"""
+
+        dev = qml.device("cirq.pasqal", wires=2)
+
+        assert dev.num_wires == 2
+        assert len(dev.qubits) == 2
+        assert dev.shots == 1000
+        assert dev.short_name == "cirq.pasqal"
+        assert dev.analytic == True
+        assert dev.control_radius == 1.0
+        assert dev.qubits == [ThreeDGridQubit(0, 0, 0), ThreeDGridQubit(1, 0, 0)]
+        assert isinstance(dev, SimulatorDevice)
+
+
+class TestDevice:
+    """Unit tests for the PasqalDevice"""
+
+    def test_device_creation(self):
+        """Tests that the cirq.pasqal device is properly created"""
+
+        dev = PasqalDevice(wires=2, shots=123, control_radius=5.0)
+
+        assert dev.num_wires == 2
+        assert len(dev.qubits) == 2
+        assert dev.shots == 123
+        assert dev.short_name == "cirq.pasqal"
+        assert dev.analytic == True
+        assert dev.control_radius == 5.0
+        assert dev.qubits == [ThreeDGridQubit(0, 0, 0), ThreeDGridQubit(1, 0, 0)]
+        assert isinstance(dev, SimulatorDevice)
+
+    @pytest.mark.parametrize(
+        "coord_idxs",
+        [
+            [(0, 0, 0), (1, 0, 0), (2, 0, 0), (3, 0, 0)],
+            [(0, 0, 0), (0, 0, 1), (0, 1, 0), (0, 1, 1)],
+            [(1, 2, 3), (3, 2, 1), (0, 0, 0), (-1, -1, -10)],
+        ],
+    )
+    def test_device_creation(self, coord_idxs):
+        """Tests that ThreeDGridQubits can be passed as an argument"""
+
+        qubits = [ThreeDGridQubit(*idxs) for idxs in coord_idxs]
+        dev = PasqalDevice(wires=4, qubits=qubits)
+
+        assert dev.qubits == qubits
+
+    def test_control_radius_negative_exception(self):
+        """Tests that an exception is raised when the supplied control_radius parameter
+        is a negative real number"""
+
+        with pytest.raises(ValueError, match="must be a non-negative real number"):
+            dev = PasqalDevice(wires=2, shots=123, control_radius=-5.0)