Release 0.44.1

Improvements 🛠

• Updated qiskit ecosystem versions: qiskit to 2.3.0 and qiskit-ibm-runtime to 0.45.0.
  (#681)

• The circuit conversion from PennyLane no longer inserts a superfluous barrier to
  delineate the circuit operations from the terminal measurements. This will allow support
  for remote backends that don't support barrier.
  (#677)

Contributors ✍️

This release contains contributions from (in alphabetical order):

Lillian M. A. Frederiksen,
Diego Guala,
Andrija Paurevic.

Release 0.44.0

Improvements 🛠

• Updated qiskit ecosystem versions: qiskit to 2.2.2, qiskit-aer to 0.17.2, and qiskit-ibm-runtime to 0.43.0.
  (#666)

• Added support for Python 3.14.
  (#679)

Internal changes ⚙️

• Fixed argnum deprecation by replacing it with argnums in tests.
  (#665)

• Updated TransformProgram to CompilePipeline to align with latest PennyLane changes.
  (#678)

• Upgraded Sphinx to version 8.1.
  (#676)

• Updated requirements files to include all dependencies explicitly.
  (#673)

Contributors ✍️

This release contains contributions from (in alphabetical order):

Runor Agbaire,
Astral Cai,
Yushao Chen,
Andrija Paurevic.

Release 0.43.0

Improvements 🛠

• Add pre-commit hook and requirements-dev.txt file for installation of development dependencies.
  (#657)

Breaking changes 💔

• The minimum supported version of PennyLane is now v0.43.0.
  (#663)

• The supported Qiskit versions are now capped at 2.2.0, meaning versions above 2.2.0 are not compatible with this release.
  (#661)

• Remove support for Qiskit 1.0 and add support for Qiskit 2.0.
  (#653)
  (#659)

• Remove support for Python 3.10 and add support for Python 3.13.
  (#646)

• QiskitDevice no longer warns or changes shots=None at initialization.
  Instead, the analytic_warning transform issues a warning only at execution time,
  and leaves shots=None unchanged; the Qiskit backend will then set it's own default for the number of shots.
  To ensure a consistent experience, use qml.set_shots(shots) on each QNode executed
  with QiskitDevice:

  dev = qml.device("qiskit.aer", wires=2)
  
  @qml.set_shots(1000)
  @qml.qnode(dev)
  def circuit():
      qml.Hadamard(wires=0)
      qml.CNOT(wires=[0, 1])
      return qml.expval(qml.PauliZ(0))
  
  # or equivalently, without the decorator:
  #  circuit = qml.set_shots(circuit, shots=1000)
  result = circuit()

  (#650)
  (#654)

Internal changes ⚙️

• Updated tests to use qml.set_shots for setting shot values on circuits.
  (#644)

Documentation 📝

• Updated documentation for connecting to IBM backends.
  (#647)

• Fix minor typos in documentation and docstrings.
  (#648)

Contributors ✍️

This release contains contributions from (in alphabetical order):

Yushao Chen,
Inho Choi,
Austin Huang,
Andrija Paurevic.

Release 0.42.0

New features since last release

Improvements 🛠

• Removes use of deprecated qml.operation.AnyWires.
  (#630)

Breaking changes 💔

• Upgrade minimum supported version of PennyLane to 0.42.0.
  (#643)

Internal changes ⚙️

• Replace DefaultExecutionConfig with ExecutionConfig() and use dataclasses.replace to update
  configurations to not mutate properties.
  (#634)

• Updated tests to keep into account that wires validation on default.qubit in PennyLane now takes place
  after the mid_circuit_measurements transform is applied during preprocessing.
  (#628)

• Bumped the readthedocs.yml action up to Ubuntu-24.04.
  (#629)

• Use new pennylane.exceptions module for custom exceptions.
  (#626)

• Plugin no longer defaults to creating a session. Instead, it decides between job mode and
  session mode and chooses one or the other based on if a user has passed in a session or not.
  (#632)

Documentation 📝

• Users are now redirected to pennylane.ai/search with the doc content type selected
  and the associated project and version filters selected when using the search bar.
  (#617)

Bug fixes 🐛

• Stops queuing a mid circuit measurement on first use of qml.from_qiskit.
  (#630)

• qml.QubitChannel in a converted noise model should now act on correct number of qubits.
  (#640)

Contributors ✍️

This release contains contributions from (in alphabetical order):

Utkarsh Azad,
Pietropaolo Frisoni,
Andrew Gardhouse,
Austin Huang,
Christina Lee,
Andrija Paurevic

Release 0.41.0.post0

Thanks to this postfix release, users are now redirected to pennylane.ai/search with the doc content type selected and the associated project and version filters selected when using the search bar.

Release 0.41.0

Bug fixes 🐛

• The layout of the circuit is now applied to the observables when it is changed on transpilation.
  (#613)

Contributors ✍️

This release contains contributions from (in alphabetical order):

Juan Felipe Huan Lew Yee

Release 0.40.1

In this release, we have pinned qiskit-aer to <0.16.1 to mitigate an incompatibility between the pennylane-qiskit plugin and the latest version of qiskit-aer, ensuring users do not encounter issues due to version mismatches. A future release will include an update to restore compatibility with the latest version.

Release 0.40.0

Breaking changes 💔

• The qml.QubitStateVector template has been removed. Instead, use :class:~pennylane.StatePrep.
  (#601)

Bug fixes 🐛

• Fixed premature session closure when using qiskit_session.
  (#608)

Contributors ✍️

This release contains contributions from (in alphabetical order):

Andrija Paurevic
Tak Hur

Release 0.39.1

In this release, we pin the version of qiskit to <1.3 in the dependencies.

The reason is that the pennylane-qiskit plugin is currently incompatible with qiskit 1.3.
We are currently working to enable compatibility with the latest qiskit version.

In the meantime, this release will prevent users from running into incompatibilities between the two versions.
Thank you for your attention.

Release 0.39.0

Improvements 🛠

• Make qiskit_session available top-level. Users can now import it as pennylane_qiskit.qiskit_session. (#593)

Breaking changes 💔

• Remove support for Python 3.9. (#597)

• Upgrade minimum supported version of PennyLane to 0.38.0. (#599)

Documentation 📝

• Added warning in the documentation of qiskit_session due to recent reports of unexpected behavior. (#594)

Bug fixes 🐛

• Fix deprecated import path for QubitDevice. (#584)

Contributors ✍️

This release contains contributions from (in alphabetical order):

Astral Cai, Lillian M. A. Frederiksen, Austin Huang, Mudit Pandey