Prepare 1.4.0 release

releasenotes/notes/1.4/prepare-1.4.0-aee22d10333374c8.yaml

@@ -0,0 +1,208 @@
+---
+prelude: |
+    The Qiskit v1.4.0 release is the final minor version release for the v1.x series.
+    This release contains minimal features, and primarily adds new 
+    deprecation warnings for API changes coming
+    in the future major version release v2.0.0. It is fully compatible with the
+    Qiskit v1.3.x releases. It is strongly recommended that you upgrade from
+    v1.3.x to v1.4.0 so that you're able to see the warnings about which
+    interfaces will change with Qiskit 2.0.0.
+    The v1.4.x release series will continue to be supported and receive
+    bugfixes  for 6 months and security fixes for 1 year after this
+    release. The fixes will take place via patch releases.
+    For more details on the release schedule and support cycle
+    see: https://docs.quantum.ibm.com/start/install#qiskit-versioning
+    which documents the release schedule in more detail.
+
+features_circuits:
+  - |
+    Added a new method, :meth:`.QuantumCircuit.estimate_duration`, to compute
+    the estimated duration of a scheduled circuit output from the :mod:`.transpiler`.
+    This should be used if you need an estimate of the full circuit duration instead
+    of the deprecated :attr:`.QuantumCircuit.duration` attribute.
+
+fixes:
+  - |
+    Fixed an issue in :meth:`.Target.has_calibration` and :meth:`.Target.get_calibration` 
+    where passing a parameterized Gate didn't work as expected.
+    Refer to `qiskit/#11657 <https://github.com/Qiskit/qiskit/issues/11657>`__ and
+    `qiskit/#11658 <https://github.com/Qiskit/qiskit/issues/11658>`__ for more 
+    information.
+
+deprecations_circuits:
+  - |
+    Subclassing :class:`.Register` or :class:`.Bit`, or any subclass of them
+    (for example, :class:`.QuantumRegister` or :class:`~.circuit.Qubit`) is deprecated as of Qiskit v1.4.0.  
+    Subclassing these types was never explicitly supported by Qiskit, and its meaning was never defined.
+    In Qiskit v2.0.0, the subclassing may become impossible due to technical limitations, 
+    and will certainly not be stored in a circuit.  This is due to the move of the data model 
+    to the Rust space to improve performance.
+  - |
+    The ``dag`` optional parameter in the constructor of :class:`DAGNode`
+    subclasses (namely :class:`DAGOpNode`), 
+    which has been unused and ignored since Qiskit v1.2.0, is now deprecated as of 
+    Qiskit v1.4.0 and will be removed in Qiskit v2.0.0.
+  - |
+    The Multiple-Control-Multiple-Target (MCMT) class in 
+    :class:`~qiskit.circuit.library.generalized_gates.MCMT` is now deprecated
+    and replaced by :class:`.MCMTGate`, which is a proper :class:`.Gate` subclass. Using
+    a gate instead of a circuit allows the compiler to reason about the object at a higher
+    level of abstraction and unlocks the use of multiple synthesis plugins.
+  - |
+    The :mod:`qiskit.circuit.classicalfunction` module, and with it the
+    :class:`.ClassicalFunction` class and its related :func:`.classical_function`
+    and :class:`.BooleanExpression` utilities, have been deprecated as of 
+    Qiskit v1.4.0 and will be removed in Qiskit v2.0.0. 
+
+    This change is performed to avoid a 
+    dependency on the external library ``tweedledum``, which is no longer 
+    compatible with all of Qiskit's supported platforms and Python versions.
+    For a similar functionality please use the :class:`.PhaseOracle` which
+    is going to have an implementation that doesn't use ``tweedledum``, and
+    the ``BitFlipOracle`` which will be added in Qiskit v2.0.0.
+
+    Until ``BitFlipOracle`` is added, a phase-flip oracle can be converted
+    to a bit-flip oracle by conditioning it on the result qubit, and applying
+    Hadamard gates before and after the application of the oracle, as in the
+    following example (where the oracle is on ``qr_x`` and the result is on ``qr_y``):
+
+    .. code-block:: python
+
+      from qiskit import QuantumRegister, QuantumCircuit
+      from qiskit.circuit.library.phase_oracle import PhaseOracle
+
+      bool_expr = "(x0 & x1 | ~x2) & x4"
+      qr_x = QuantumRegister(4, "x")
+      qr_y = QuantumRegister(1, "y")
+
+      bit_flip_oracle = QuantumCircuit(qr_x, qr_y)
+      phase_flip_oracle = PhaseOracle(bool_expr)
+      controlled_phase_flip_oracle = phase_flip_oracle.control(1)
+      bit_flip_oracle.h(qr_y)
+      bit_flip_oracle.compose(controlled_phase_flip_oracle, qubits=[*qr_y, *qr_x], inplace=True)
+      bit_flip_oracle.h(qr_y)
+
+      print(bit_flip_oracle)
+
+    Which results in
+
+    .. code-block:: text
+
+                ┌───────────────┐     
+      x_0: ─────┤0              ├─────
+                │               │     
+      x_1: ─────┤1              ├─────
+                │  Phase Oracle │     
+      x_2: ─────┤2              ├─────
+                │               │     
+      x_3: ─────┤3              ├─────
+          ┌───┐└───────┬───────┘┌───┐
+       y: ┤ H ├────────■────────┤ H ├
+          └───┘                 └───┘
+
+deprecations_providers:
+  - |
+    The :class:`.BackendV2Converter` class and  :func:`.convert_to_target` functions 
+    have been deprecated in Qiskit v1.4.0 following the deprecation of :class:`.BackendV1`.
+    :func:`.convert_to_target` is used to build a :class:`.Target` instance 
+    from a series of objects from the deprecated :class:`.BackendV1` workflow: 
+    :class:`.BackendConfiguration`, :class:`.BackendProperties` and :class:`.PulseDefaults`.
+    :class:`.BackendV2Converter` is used for converting :class:`.BackendV1` 
+    to :class:`.BackendV2`, and cannot be maintained once :class:`.BackendV1` is removed.
+  - |
+    The :meth:`.BasicSimulator.run_experiment` method has been deprecated 
+    and will be removed in Qiskit v2.0.0.
+    The method takes a :class:`.QasmQobjExperiment` as input argument, 
+    which has been deprecated together
+    with the :class:`.Qobj` class and other related functionality. 
+    You can call :meth:`.BasicSimulator.run` 
+    with a :class:`.QuantumCircuit` input instead.
+
+deprecations_synthesis:
+  - |
+    The signature of the argument ``atomic_evolution`` in the constructor of the classes
+    :class:`.LieTrotter`, :class:`.ProductFormula`, and 
+    :class:`.SuzukiTrotter` was modified in Qiskit v1.2.0 to improve the visualization
+    of the output circuit. The older signature has now been deprecated in favor of the 
+    new alternative. From Qiskit 2.0.0, only the new alternative will be valid.
+
+    To migrate, please modify the callable from
+    ``Callable[[Pauli | SparsePauliOp, float], QuantumCircuit]`` to
+    ``Callable[[QuantumCircuit, Pauli | SparsePauliOp, float], None]``.
+
+deprecations_transpiler:
+  - |
+    The :attr:`.DAGOpNode.sort_key`, :attr:`.DAGOutNode.sort_key`, and
+    :attr:`.DAGInNode.sort_key` attributes have been deprecated and will be
+    removed in the Qiskit v2.0.0 release. These attributes were originally used
+    as a lexicographical key for topological sorting nodes in a 
+    :class:`.DAGCircuit`. However, the key is no longer used for this
+    as the sorting is done internally in Rust code now. If you're using this
+    attribute, you can recreate the key from the other attributes
+    of a node. For example, you can use a function like::
+
+        def get_sort_key(node: DAGNode):
+            if isinstance(node, (DAGInNode, DAGOutNode)):
+                return str(node.wire)
+            return ",".join(
+                f"{dag.find_bit(q).index:04d}" for q in itertools.chain(node.qargs, node.cargs)
+            )
+
+    which will generate a string like the sort key does.
+  - |
+    The following uses of the :class:`.BackendProperties` object in the transpilation pipeline
+    have been deprecated as of Qiskit v1.4.0 and will be removed in Qiskit v2.0.0:
+
+    * ``backend_prop`` input argument in :class:`.DenseLayout`
+    * ``properties`` input argument in :class:`.VF2Layout`
+    * ``properties`` and ``coupling_map`` input arguments in :class:`.VF2PostLayout`. Note that ``coupling_map`` was only used in the presence of ``properties``.
+    * ``backend_props`` input argument in :class:`.UnitarySynthesis`
+    * ``backend_properties`` input argument in :class:`.PassManagerConfig`
+    * ``backend_properties`` in  :meth:`.Target.from_configuration`
+    * ``backend_properties`` in :func:`.generate_routing_passmanager`
+    * ``backend_properties`` in :func:`.generate_translation_passmanager`
+
+    The :class:`.BackendProperties` class has been deprecated since Qiskit v1.2.0, together with 
+    other elements from the :class:`.BackendV1` workflow, and will be removed in Qiskit v2.0.0. 
+    The alternative path for communicating hardware information to the transpilation argument is the
+    :class:`.Target` class, which can be set using the ``target`` input argument.
+    Specific instruction properties such as gate errors or durations can be added to a :class:`.Target` upon 
+    construction through the :meth:`.Target.add_instruction` method.
+
+    In the case of :func:`.generate_routing_passmanager` and :func:`.generate_translation_passmanager`,
+    the ``backend_properties`` argument is optional and is superseded when the required ``target`` 
+    argument is populated. Usage of the argument can safely be removed in 1.x as long as you were 
+    passing in a target, which was the recommended use.
+
+  - |
+    The Pulse deprecation in Qiskit v1.3.0, included calibration builder passes
+    such as :class:`.RXCalibrationBuilder`. The
+    :class:`.NormalizeRXAngle` pass is a requirement of :class:`.RXCalibrationBuilder`;
+    hence, it is being deprecated in Qiskit v1.4.0. The :func:`.rzx_templates`
+    function in the calibration module is also being deprecated as it is not used in our codebase.
+
+deprecations_visualization:
+  - |
+    The parameters ``show_idle`` and ``show_barrier`` in the timeline drawers are 
+    deprecated as of Qiskit v1.4.0. The alternatives are, respectively, the 
+    ``idle_wires`` and ``plot_barriers`` parameters, introduced in Qiskit v1.1.0,
+    which are fully equivalent.
+    The legacy parameter names will be removed in Qiskit v2.0.0.
+  - |
+    In Qiskit v1.4.0, the timeline drawer :func:`~qiskit.visualization.timeline.interface.draw` function
+    will issue a deprecation warning if a ``target`` is not specified to get the duration
+    of instructions. From Qiskit v2.0.0 on, ``target`` will be required and 
+    :func:`~qiskit.visualization.timeline.interface.draw` will fail if it is not specified.
+
+other:
+  - |
+    Passing ``property_set`` as an arbitrary keyword argument to the :meth:`~.BasePassManager.run`
+    method of a subclass of :class:`.BasePassManager` will change behavior in Qiskit v2.0.0.  It is
+    currently forwarded to the internal representation converting functions of the pass manager, as
+    is any arbitrary keyword argument to that method.  Starting from Qiskit v2.0.0, the option will
+    instead be used to set the seed of the :class:`.PropertySet` for the pipeline run, and the
+    argument will not be passed to the conversion functions.
+
+    This note only concerns implementers of subclasses of :class:`.BasePassManager` who have chosen
+    their ``_passmanager_frontend`` and ``_passmanager_backend`` implementations to accept a 
+    keyword argument called ``property_set``.