Update AQT Backend

cirq-aqt/cirq_aqt/aqt_device.py

@@ -25,6 +25,7 @@
 """
 
 import json
+from enum import Enum
 from typing import Any, cast, Dict, Iterable, List, Optional, Sequence, Set, Tuple, Union
 
 import networkx as nx
@@ -36,11 +37,18 @@
 gate_dict = {'X': cirq.X, 'Y': cirq.Y, 'Z': cirq.Z, 'MS': cirq.XX, 'R': cirq.PhasedXPowGate}
 
 
+class OperationString(Enum):
+    MS = "MS"
+    Z = "Z"
+    R = "R"
+    MEASURE = "Meas"
+
+
 def get_op_string(op_obj: cirq.Operation) -> str:
     """Find the string representation for a given gate or operation.
 
     Args:
-        op_obj: Gate or operation object. Gate must be one of: XXPowGate, XPowGate, YPowGate,
+        op_obj: Gate or operation object. Gate must be one of: XXPowGate,
             ZPowGate, PhasedXPowGate, or MeasurementGate.
 
     Returns:
@@ -50,20 +58,16 @@ def get_op_string(op_obj: cirq.Operation) -> str:
         ValueError: If the gate is not one of the supported gates.
     """
     if isinstance(op_obj.gate, cirq.XXPowGate):
-        op_str = 'MS'
-    elif isinstance(op_obj.gate, cirq.XPowGate):
-        op_str = 'X'
-    elif isinstance(op_obj.gate, cirq.YPowGate):
-        op_str = 'Y'
+        op_str = OperationString.MS
     elif isinstance(op_obj.gate, cirq.ZPowGate):
-        op_str = 'Z'
+        op_str = OperationString.Z
     elif isinstance(op_obj.gate, cirq.PhasedXPowGate):
-        op_str = 'R'
+        op_str = OperationString.R
     elif isinstance(op_obj.gate, cirq.MeasurementGate):
-        op_str = 'Meas'
+        op_str = OperationString.MEASURE
     else:
         raise ValueError(f'Got unknown gate on operation: {op_obj}.')
-    return op_str
+    return str(op_str)
 
 
 class AQTNoiseModel(cirq.NoiseModel):
@@ -97,6 +101,7 @@ def noisy_moment(
             for qubit in op.qubits:
                 noise_list.append(noise_op.on(qubit))
             noise_list += self.get_crosstalk_operation(op, system_qubits)
+
         return list(moment) + noise_list
 
     def get_crosstalk_operation(
@@ -108,6 +113,9 @@ def get_crosstalk_operation(
             operation: Ideal operation
             system_qubits: Tuple of line qubits
 
+        Raises:
+            RuntimeError: if operation applies no gate.
+
         Returns:
             List of operations including crosstalk
         """
@@ -122,16 +130,20 @@ def get_crosstalk_operation(
             for neigh_idx in neighbors:
                 if neigh_idx >= 0 and neigh_idx < num_qubits:
                     xtlk_arr[neigh_idx] = self.noise_op_dict['crosstalk']
+
         for idx in idx_list:
             xtlk_arr[idx] = 0
         xtlk_op_list = []
         op_str = get_op_string(operation)
         gate = cast(cirq.EigenGate, gate_dict[op_str])
+
         if len(operation.qubits) == 1:
             for idx in xtlk_arr.nonzero()[0]:
                 exponent = operation.gate.exponent  # type:ignore
                 exponent = exponent * xtlk_arr[idx]
-                xtlk_op = gate.on(system_qubits[idx]) ** exponent
+                if operation.gate is None:
+                    raise RuntimeError("Operation applies no gate.")
+                xtlk_op = operation.gate.on(system_qubits[idx]) ** exponent
                 xtlk_op_list.append(xtlk_op)
         elif len(operation.qubits) == 2:
             for op_qubit in operation.qubits:
@@ -216,10 +228,14 @@ def simulate_samples(self, repetitions: int) -> cirq.Result:
             noise_model = cirq.NO_NOISE
         else:
             noise_model = AQTNoiseModel()
+
         if self.circuit == cirq.Circuit():
             raise RuntimeError('Simulate called without a valid circuit.')
+
         sim = cirq.DensityMatrixSimulator(noise=noise_model)
+
         result = sim.run(self.circuit, repetitions=repetitions)
+
         return result
 
 
@@ -342,9 +358,8 @@ def get_aqt_device(num_qubits: int) -> Tuple[AQTDevice, List[cirq.LineQubit]]:
 def get_default_noise_dict() -> Dict[str, Any]:
     """Returns the current noise parameters"""
     default_noise_dict = {
-        'X': cirq.depolarize(1e-3),
-        'Y': cirq.depolarize(1e-3),
-        'Z': cirq.depolarize(1e-3),
+        'R': cirq.depolarize(1e-3),
+        'Z': cirq.depolarize(0),
         'MS': cirq.depolarize(1e-2),
         'crosstalk': 0.03,
     }

cirq-aqt/cirq_aqt/aqt_device_metadata.py

@@ -53,8 +53,6 @@ def __init__(
         self._gate_durations = {
             cirq.GateFamily(cirq.MeasurementGate): self._measurement_duration,
             cirq.GateFamily(cirq.XXPowGate): self._twoq_gates_duration,
-            cirq.GateFamily(cirq.XPowGate): self._oneq_gates_duration,
-            cirq.GateFamily(cirq.YPowGate): self._oneq_gates_duration,
             cirq.GateFamily(cirq.ZPowGate): self._oneq_gates_duration,
             cirq.GateFamily(cirq.PhasedXPowGate): self._oneq_gates_duration,
         }

cirq-aqt/cirq_aqt/aqt_device_metadata_test.py

@@ -45,7 +45,7 @@ def test_aqtdevice_metadata(metadata, qubits):
     assert len(edges) == 10
     assert all(q0 != q1 for q0, q1 in edges)
     assert AQTTargetGateset() == metadata.gateset
-    assert len(metadata.gate_durations) == 6
+    assert len(metadata.gate_durations) == 4
 
 
 def test_aqtdevice_duration_of(metadata, qubits):