Update code that is pending deprecation

CHANGELOG.md

@@ -6,6 +6,13 @@
   now been removed. The `upload_vqe_runner` and `delete_vqe_runner` functions have also been removed.
   [(#298)](https://github.com/PennyLaneAI/pennylane-qiskit/pull/298)
 
+### Improvements
+
+* Updated many small things across the plugin to match re-works and deprecations in `qiskit`. The plugin
+  can still be used in the same way as before. However, we suggest you authenticate with
+  `qiskit_ibm_provider.IBMProvider` instead of `qiskit.IBMQ` from now on, as the latter is deprecated.
+  [(#301)](https://github.com/PennyLaneAI/pennylane-qiskit/pull/301)
+
 ### Contributors
 
 This release contains contributions from (in alphabetical order):

README.rst

@@ -75,7 +75,10 @@ in the source folder. Tests restricted to a specific provider can be run by exec
     only be run if a ``ibmqx_token`` for the
     `IBM Q experience <https://quantum-computing.ibm.com/>`_ is
     configured in the `PennyLane configuration file
-    <https://pennylane.readthedocs.io/en/latest/introduction/configuration.html>`_.
+    <https://pennylane.readthedocs.io/en/latest/introduction/configuration.html>`_, if the token is
+    exported in your environment under the name ``IBMQX_TOKEN``, or if you have previously saved your
+    account credentials using the
+    `new IBMProvider <https://qiskit.org/ecosystem/ibm-provider/stubs/qiskit_ibm_provider.IBMProvider.html>`_
 
     If this is the case, running ``make test`` also executes tests on the ``ibmq`` device.
     By default tests on the ``ibmq`` device run with ``ibmq_qasm_simulator`` backend

doc/devices/aer.rst

@@ -45,7 +45,7 @@ or, alternatively,
 
 .. code-block:: python
 
-    from qiskit import Aer
+    from qiskit_aer import Aer
     Aer.backends()
 
 .. note::
@@ -84,7 +84,7 @@ The options are set via additional keyword arguments:
     )
 
 For more information on available methods and their options, please visit the `AerSimulator
-documentation <https://qiskit.org/documentation/stubs/qiskit.providers.aer.AerSimulator.html>`_.
+documentation <https://qiskit.org/ecosystem/aer/stubs/qiskit_aer.AerSimulator.html>`_.
 
 .. warning::
 
@@ -103,7 +103,7 @@ which you can instantiate and apply to the device as follows
     import pennylane as qml
 
     import qiskit
-    import qiskit.providers.aer.noise as noise
+    from qiskit_aer import noise
 
     # Error probabilities
     prob_1 = 0.001  # 1-qubit gate

doc/devices/ibmq.rst

@@ -15,8 +15,8 @@ IBM Q account. If the device finds no account it will raise an error:
 
     'No active IBM Q account, and no IBM Q token provided.
 
-You can use the ``qiskit.IBMQ.save_account("<my_token>")`` function to permanently store an account,
-and the ``qiskit.IBMQ.load_account()`` function to load the stored account in a given session.
+You can use the ``qiskit_ibm_provider.IBMProvider.save_account("<my_token>")`` function to permanently
+store an account, and the account will be automatically used from then onward.
 Alternatively, you can specify the token with PennyLane via the
 `PennyLane configuration file <https://pennylane.readthedocs.io/en/latest/introduction/configuration.html>`__ by
 adding the section
@@ -34,6 +34,11 @@ You may also directly pass your IBM Q API token to the device:
 
     dev = qml.device('qiskit.ibmq', wires=2, backend='ibmq_qasm_simulator', ibmqx_token="XXX")
 
+You may also save your token as an environment variable by running the following in a terminal:
+
+.. code::
+
+    export IBMQX_TOKEN=<my_token>
 
 .. warning:: Never publish code containing your token online.
 
@@ -58,8 +63,8 @@ Custom providers can be passed as arguments when a ``qiskit.ibmq`` device is cre
 
 .. code-block:: python
 
-    from qiskit import IBMQ
-    provider = IBMQ.enable_account('XYZ')
+    from qiskit_ibm_provider import IBMProvider
+    provider = IBMProvider("XYZ")
 
     import pennylane as qml
     dev = qml.device('qiskit.ibmq', wires=2, backend='ibmq_qasm_simulator', provider=provider)
@@ -76,4 +81,4 @@ Custom provider options can also be passed as keyword arguments when creating a
                      ibmqx_token='XXX', hub='MYHUB', group='MYGROUP', project='MYPROJECT')
 
 More details on Qiskit providers can be found
-in the `IBMQ provider documentation <https://qiskit.org/documentation/apidoc/ibmq-provider.html>`_.
+in the `IBMQ provider documentation <https://qiskit.org/ecosystem/ibm-provider/stubs/qiskit_ibm_provider.IBMProvider.html>`_.

doc/devices/runtime.rst

@@ -29,15 +29,14 @@ We created a wrapper to use PennyLane objects while solving VQE problems on IBM
 
     from pennylane_qiskit import vqe_runner
 
-    IBMQ.enable_account(token)
-
     def vqe_circuit(params):
         qml.RX(params[0], wires=0)
         qml.RY(params[1], wires=0)
 
     coeffs = [1, 1]
     obs = [qml.PauliX(0), qml.PauliZ(0)]
     hamiltonian = qml.Hamiltonian(coeffs, obs)
+    shots = 8000
 
     job = vqe_runner(
         backend="ibmq_qasm_simulator",

doc/index.rst

@@ -67,7 +67,7 @@ follows:
 
 PennyLane chooses the ``qasm_simulator`` as the default backend if no backend is specified.
 For more details on the ``qasm_simulator``, including available backend options, see
-`Qiskit Qasm Simulator documentation <https://qiskit.org/documentation/stubs/qiskit.providers.aer.QasmSimulator.html>`_.
+`Qiskit Qasm Simulator documentation <https://qiskit.org/ecosystem/aer/stubs/qiskit_aer.QasmSimulator.html>`_.
 
 Tutorials
 ~~~~~~~~~

doc/requirements.txt

@@ -10,6 +10,7 @@ pygments==2.7.4
 pygments-github-lexers==0.0.5
 qiskit==0.42.1
 qiskit-ibm-runtime==0.9.3
+qiskit-ibm-provider==0.5.2
 sphinxcontrib-bibtex==2.5.0
 sphinx-automodapi==0.14.1
 pennylane-sphinx-theme

pennylane_qiskit/aer.py

@@ -16,7 +16,7 @@
 evaluation and differentiation of Qiskit Aer's C++ simulator
 using PennyLane.
 """
-import qiskit
+import qiskit_aer
 
 from .qiskit_device import QiskitDevice
 
@@ -31,16 +31,16 @@ class AerDevice(QiskitDevice):
     a range of transpile options can be given as kwargs.
 
     For more information on backends, please visit the
-    `Aer provider documentation <https://qiskit.org/documentation/apidoc/aer_provider.html>`_.
+    `qiskit_aer documentation <https://qiskit.org/ecosystem/aer/index.html>`_.
 
     Args:
         wires (int or Iterable[Number, str]]): Number of subsystems represented by the device,
             or iterable that contains unique labels for the subsystems as numbers (i.e., ``[-1, 0, 2]``)
             or strings (``['ancilla', 'q1', 'q2']``).
         backend (str): the desired backend
         method (str): The desired simulation method. A list of supported simulation
-            methods can be returned using ``qiskit.Aer.available_methods()``, or by referring
-            to the ``AerSimulator`` `documentation <https://qiskit.org/documentation/stubs/qiskit.providers.aer.AerSimulator.html>`__.
+            methods can be returned using ``qiskit_aer.AerSimulator().available_methods()``, or by referring
+            to the ``AerSimulator`` `documentation <https://qiskit.org/ecosystem/aer/stubs/qiskit_aer.AerSimulator.html>`__.
         shots (int or None): number of circuit evaluations/random samples used
             to estimate expectation values and variances of observables. For statevector backends,
             setting to ``None`` results in computing statistics like expectation values and variances analytically.
@@ -49,7 +49,7 @@ class AerDevice(QiskitDevice):
         name (str): The name of the circuit. Default ``'circuit'``.
         compile_backend (BaseBackend): The backend used for compilation. If you wish
             to simulate a device compliant circuit, you can specify a backend here.
-        noise_model (NoiseModel): NoiseModel Object from ``qiskit.providers.aer.noise``
+        noise_model (NoiseModel): NoiseModel Object from ``qiskit_aer.noise``
     """
 
     # pylint: disable=too-many-arguments
@@ -60,4 +60,4 @@ def __init__(self, wires, shots=1024, backend="aer_simulator", method="automatic
         if method != "automatic":
             backend += "_" + method
 
-        super().__init__(wires, provider=qiskit.Aer, backend=backend, shots=shots, **kwargs)
+        super().__init__(wires, provider=qiskit_aer.Aer, backend=backend, shots=shots, **kwargs)

pennylane_qiskit/ibmq.py

@@ -18,8 +18,9 @@
 """
 import os
 
-from qiskit import IBMQ
-from qiskit.providers.ibmq.exceptions import IBMQAccountError
+from qiskit_ibm_provider import IBMProvider
+from qiskit_ibm_provider.exceptions import IBMAccountError
+from qiskit_ibm_provider.accounts.exceptions import AccountsError
 
 from .qiskit_device import QiskitDevice
 
@@ -41,7 +42,7 @@ class IBMQDevice(QiskitDevice):
             or strings (``['ancilla', 'q1', 'q2']``). Note that for some backends, the number
             of wires has to match the number of qubits accessible.
         provider (Provider): The IBM Q provider you wish to use. If not provided,
-            then the default provider returned by ``IBMQ.get_provider()`` is used.
+            then the default provider returned by ``IBMProvider()`` is used.
         backend (str): the desired provider backend
         shots (int): number of circuit evaluations/random samples used
             to estimate expectation values and variances of observables
@@ -51,7 +52,7 @@ class IBMQDevice(QiskitDevice):
             variable ``IBMQX_TOKEN`` is used.
         ibmqx_url (str): The IBM Q URL. If not provided, the environment
             variable ``IBMQX_URL`` is used, followed by the default URL.
-        noise_model (NoiseModel): NoiseModel Object from ``qiskit.providers.aer.noise``.
+        noise_model (NoiseModel): NoiseModel Object from ``qiskit_aer.noise``.
             Only applicable for simulator backends.
         hub (str): Name of the provider hub.
         group (str): Name of the provider group.
@@ -67,9 +68,10 @@ def __init__(self, wires, provider=None, backend="ibmq_qasm_simulator", shots=10
         hub = kwargs.get("hub", "ibm-q")
         group = kwargs.get("group", "open")
         project = kwargs.get("project", "main")
+        instance = "/".join([hub, group, project])
 
         # get a provider
-        p = provider or IBMQ.get_provider(hub=hub, group=group, project=project)
+        p = provider or IBMProvider(instance=instance)
 
         super().__init__(wires=wires, provider=p, backend=backend, shots=shots, **kwargs)
 
@@ -101,41 +103,26 @@ def connect(kwargs):
     Args:
         kwargs(dict): dictionary that contains the token and the url"""
 
+    hub = kwargs.get("hub", "ibm-q")
+    group = kwargs.get("group", "open")
+    project = kwargs.get("project", "main")
+    instance = "/".join([hub, group, project])
+
     token = kwargs.get("ibmqx_token", None) or os.getenv("IBMQX_TOKEN")
     url = kwargs.get("ibmqx_url", None) or os.getenv("IBMQX_URL")
 
-    # TODO: remove "no cover" when #173 is resolved
-    if token:  # pragma: no cover
-        # token was provided by the user, so attempt to enable an
-        # IBM Q account manually
-        def login():
-            ibmq_kwargs = {"url": url} if url is not None else {}
-            IBMQ.enable_account(token, **ibmq_kwargs)
-
-        active_account = IBMQ.active_account()
-        if active_account is None:
-            login()
-        else:
-            # There is already an active account:
-            # If the token is the same, do nothing.
-            # If the token is different, authenticate with the new account.
-            if active_account["token"] != token:
-                IBMQ.disable_account()
-                login()
-    else:
-        # check if an IBM Q account is already active.
-        #
-        # * IBMQ v2 credentials stored in active_account().
-        #   If no accounts are active, it returns None.
-
-        if IBMQ.active_account() is None:
-            # no active account
-            try:
-                # attempt to load a v2 account stored on disk
-                IBMQ.load_account()
-            except IBMQAccountError:
-                # attempt to enable an account manually using
-                # a provided token
-                raise IBMQAccountError(
-                    "No active IBM Q account, and no IBM Q token provided."
-                ) from None
+    saved_accounts = IBMProvider.saved_accounts()
+    if not token:
+        if not saved_accounts:
+            raise IBMAccountError("No active IBM Q account, and no IBM Q token provided.")
+        try:
+            IBMProvider(url=url, instance=instance)
+        except AccountsError as e:
+            raise AccountsError(
+                f"Accounts were found ({set(saved_accounts)}), but all failed to load."
+            ) from e
+        return
+    for account in saved_accounts.values():
+        if account["token"] == token:
+            return
+    IBMProvider.save_account(token=token, url=url, instance=instance)

pennylane_qiskit/qiskit_device.py

@@ -158,7 +158,13 @@ def __init__(self, wires, provider, backend, shots=1024, **kwargs):
 
         self.provider = provider
         self.backend_name = backend
-        self._capabilities["backend"] = [b.name() for b in self.provider.backends()]
+
+        def _get_backend_name(name):
+            return name if isinstance(name, str) else name()
+
+        self._capabilities["backend"] = [
+            _get_backend_name(b.name) for b in self.provider.backends()
+        ]
         self._capabilities["returns_state"] = backend in self._state_backends
 
         # Check that the backend exists

pennylane_qiskit/runtime_devices.py

@@ -18,7 +18,8 @@
 
 import numpy as np
 
-from qiskit.providers.ibmq import RunnerResult
+from qiskit_ibm_runtime import QiskitRuntimeService
+from qiskit_ibm_runtime.constants import RunnerResult
 from pennylane_qiskit.ibmq import IBMQDevice
 
 
@@ -55,6 +56,7 @@ class IBMQCircuitRunnerDevice(IBMQDevice):
     def __init__(self, wires, provider=None, backend="ibmq_qasm_simulator", shots=1024, **kwargs):
         self.kwargs = kwargs
         super().__init__(wires=wires, provider=provider, backend=backend, shots=shots, **kwargs)
+        self.runtime_service = QiskitRuntimeService(channel="ibm_quantum")
 
     def batch_execute(self, circuits):
         compiled_circuits = self.compile_circuits(circuits)
@@ -65,10 +67,10 @@ def batch_execute(self, circuits):
             program_inputs[kwarg] = self.kwargs.get(kwarg)
 
         # Specify the backend.
-        options = {"backend_name": self.backend.name()}
+        options = {"backend": self.backend.name}
 
         # Send circuits to the cloud for execution by the circuit-runner program.
-        job = self.provider.runtime.run(
+        job = self.runtime_service.run(
             program_id="circuit-runner", options=options, inputs=program_inputs
         )
         self._current_job = job.result(decoder=RunnerResult)
@@ -140,20 +142,21 @@ class IBMQSamplerDevice(IBMQDevice):
     def __init__(self, wires, provider=None, backend="ibmq_qasm_simulator", shots=1024, **kwargs):
         self.kwargs = kwargs
         super().__init__(wires=wires, provider=provider, backend=backend, shots=shots, **kwargs)
+        self.runtime_service = QiskitRuntimeService(channel="ibm_quantum")
 
     def batch_execute(self, circuits):
         compiled_circuits = self.compile_circuits(circuits)
 
         program_inputs = {"circuits": compiled_circuits}
 
         if "circuits_indices" not in self.kwargs:
-            circuit_indices = list(range(0, len(compiled_circuits)))
+            circuit_indices = list(range(len(compiled_circuits)))
             program_inputs["circuit_indices"] = circuit_indices
         else:
             circuit_indices = self.kwargs.get("circuit_indices")
 
         if "run_options" in self.kwargs:
-            if not "shots" in self.kwargs["run_options"]:
+            if "shots" not in self.kwargs["run_options"]:
                 self.kwargs["run_options"]["shots"] = self.shots
         else:
             self.kwargs["run_options"] = {"shots": self.shots}
@@ -162,11 +165,9 @@ def batch_execute(self, circuits):
             program_inputs[kwarg] = self.kwargs.get(kwarg)
 
         # Specify the backend.
-        options = {"backend_name": self.backend.name()}
+        options = {"backend": self.backend.name}
         # Send circuits to the cloud for execution by the sampler program.
-        job = self.provider.runtime.run(
-            program_id="sampler", options=options, inputs=program_inputs
-        )
+        job = self.runtime_service.run(program_id="sampler", options=options, inputs=program_inputs)
         self._current_job = job.result()
 
         results = []
@@ -199,14 +200,13 @@ def generate_samples(self, circuit_id=None):
         Returns:
              array[complex]: array of samples in the shape ``(dev.shots, dev.num_wires)``
         """
-        counts = self._current_job.get("quasi_dists")[circuit_id]
+        counts = self._current_job.quasi_dists[circuit_id]
         keys = list(counts.keys())
 
-        number_of_states = 2 ** len(keys[0])
-
-        # Convert state to int
-        for i, elem in enumerate(keys):
-            keys[i] = int(elem, 2)
+        if isinstance(keys[0], str):
+            for i, elem in enumerate(keys):
+                keys[i] = int(elem, 2)
+        number_of_states = len(keys)
 
         values = list(counts.values())
         states, probs = zip(*sorted(zip(keys, values)))

pennylane_qiskit/vqe_runtime_runner.py

@@ -193,7 +193,7 @@ def vqe_runner(
     project = kwargs.get("project", "main")
     instance = "/".join([hub, group, project])
 
-    options = {"backend_name": backend, "instance": instance}
+    options = {"backend": backend, "instance": instance}
 
     service = QiskitRuntimeService(channel="ibm_quantum", token=os.getenv("IBMQX_TOKEN"))
     rt_job = RuntimeJobWrapper()

requirements.txt

@@ -26,9 +26,9 @@ pycparser==2.21
 python-constraint==1.4.0
 python-dateutil==2.8.2
 qiskit==0.42.1
-qiskit-aer==0.10.1
+qiskit-aer==0.12.0
 qiskit-ibm-runtime==0.9.3
-qiskit-ibmq-provider==0.18.3
+qiskit-ibm-provider==0.5.2
 qiskit-ignis==0.7.1
 qiskit-terra==0.23.3
 requests==2.27.1