retire harmony (remove defaults)

doc/devices.rst

@@ -46,7 +46,7 @@ installed, you can use this device directly in PennyLane by specifying ``"ionq.q
     import pennylane as qml
     from pennylane_ionq import ops
 
-    dev = qml.device("ionq.qpu", backend="harmony", wires=2)
+    dev = qml.device("ionq.qpu", backend="aria-1", wires=2)
 
     @qml.qnode(dev)
     def circuit(x, y):

pennylane_ionq/device.py

@@ -127,7 +127,7 @@
     # and therefore does not support the Hermitian observable.
     observables = {"PauliX", "PauliY", "PauliZ", "Hadamard", "Identity", "Prod"}
 
     def __init__(
         self,
         wires,
         *,
@@ -171,13 +171,6 @@
         }
         if self.error_mitigation is not None:
             self.job["error_mitigation"] = self.error_mitigation
-        if self.job["target"] == "qpu":
-            self.job["target"] = "qpu.harmony"
-            warnings.warn(
-                "The ionq_qpu backend is deprecated. Defaulting to ionq_qpu.harmony.",
-                UserWarning,
-                stacklevel=2,
-            )
 
     def set_current_circuit_index(self, circuit_index):
         """Sets the index of the current circuit for which operations are applied upon.
@@ -274,7 +267,7 @@
         if len(operations) == 0 and len(rotations) == 0:
             warnings.warn("Circuit is empty. Empty circuits return failures. Submitting anyway.")
 
         for i, operation in enumerate(operations):
             self._apply_operation(operation, circuit_index)
 
         # diagonalize observables
@@ -299,7 +292,7 @@
         if len(operations) == 0 and len(rotations) == 0:
             warnings.warn("Circuit is empty. Empty circuits return failures. Submitting anyway.")
 
         for i, operation in enumerate(operations):
             self._apply_operation(operation)
 
         # diagonalize observables
@@ -459,8 +452,8 @@
             or iterable that contains unique labels for the subsystems as numbers (i.e., ``[-1, 0, 2]``)
             or strings (``['ancilla', 'q1', 'q2']``).
         gateset (str): the target gateset, either ``"qis"`` or ``"native"``. Defaults to ``qis``.
-        backend (str): Optional specifier for an IonQ backend. Can be ``"harmony"``, ``"aria-1"``, etc.
-            Default to ``harmony``.
+        backend (str): Optional specifier for an IonQ backend. Can be ``"aria-1"``, ``"forte-1"``, etc.
+            Defaults to ``"aria-1"``.
         shots (int, list[int]): Number of circuit evaluations/random samples used to estimate
             expectation values of observables. Defaults to 1024. If a list of integers is passed, the
             circuit evaluations are batched over the list of shots.
@@ -480,21 +473,19 @@
     name = "IonQ QPU PennyLane plugin"
     short_name = "ionq.qpu"
 
     def __init__(
         self,
         wires,
         *,
         gateset="qis",
         shots=1024,
-        backend="harmony",
+        backend="aria-1",
         error_mitigation=None,
         sharpen=None,
         api_key=None,
     ):
-        target = "qpu"
         self.backend = backend
-        if self.backend is not None:
-            target += "." + self.backend
+        target = f"qpu.{self.backend}"
         super().__init__(
             wires=wires,
             target=target,

tests/test_device.py

@@ -218,7 +218,22 @@ def test_prob_no_results(self, d):
         dev = qml.device(d, wires=1, shots=1)
         assert dev.prob is None
 
-    @pytest.mark.parametrize("backend", ["harmony", "aria-1", "aria-2", "forte-1", None])
+    def test_probability(self):
+        """Test that device.probability works."""
+        dev = qml.device("ionq.simulator", wires=2)
+        dev.target_device._samples = np.array([[1, 1], [1, 1], [0, 0], [0, 0]])
+        assert np.array_equal(dev.probability(shot_range=(0, 2)), [0, 0, 0, 1])
+
+        uniform_prob = [0.25] * 4
+        with patch(
+            "pennylane_ionq.device.SimulatorDevice.prob", new_callable=PropertyMock
+        ) as mock_prob:
+            mock_prob.return_value = uniform_prob
+            assert np.array_equal(dev.probability(), uniform_prob)
+
+    @pytest.mark.parametrize(
+        "backend", ["aria-1", "aria-2", "forte-1", None]
+    )
     def test_backend_initialization(self, backend):
         """Test that the device initializes with the correct backend."""
         dev = qml.device(