Merge branch 'master' into tree_mcm_tests

.github/workflows/install_deps/action.yml

@@ -15,7 +15,7 @@ inputs:
  jax_version:
  description: The version of JAX to install for any job that requires JAX
  required: false
- default: '0.4.23'
+ default: '0.4.28'
  install_tensorflow:
  description: Indicate if TensorFlow should be installed or not
  required: false
@@ -86,7 +86,7 @@ runs:
  if: inputs.install_jax == 'true'
  env:
  JAX_VERSION: ${{ inputs.jax_version != '' && format('=={0}', inputs.jax_version) || '' }}
- run: pip install "jax${{ env.JAX_VERSION}}" "jaxlib${{ env.JAX_VERSION }}" scipy~=1.12.0
+ run: pip install "jax${{ env.JAX_VERSION}}" "jaxlib${{ env.JAX_VERSION }}"
 
  - name: Install additional PIP packages
  shell: bash

doc/code/qml_qinfo.rst

@@ -4,6 +4,13 @@ qml.qinfo
 Overview
 --------
 
+.. warning::
+
+ The ``qinfo`` module is deprecated and scheduled to be removed in v0.40. Most quantum information transforms
+ are available as measurement processes (see the :mod:`~pennylane.measurements` module for more details).
+ Additionally, the transforms are also available as standalone functions in the :mod:`~pennylane.math` and
+ :mod:`~pennylane.gradients` modules.
+
 This module provides a collection of methods to return quantum information quantities from :class:`~.QNode`
 returning :func:`~pennylane.state`.
 
@@ -15,8 +22,4 @@ Transforms
 .. automodapi:: pennylane.qinfo.transforms
  :no-heading:
  :no-inherited-members:
- :skip: metric_tensor
- :skip: adjoint_metric_tensor
  :skip: transform
- :skip: classical_fisher
- :skip: quantum_fisher

doc/development/deprecations.rst

@@ -9,14 +9,37 @@ deprecations are listed below.
 Pending deprecations
 --------------------
 
+* The ``'ancilla'`` argument for :func:`~pennylane.iterative_qpe` has been deprecated. Instead, use the ``'aux_wire'``
+ argument.
+
+ - Deprecated in v0.39
+ - Will be removed in v0.40
+
+* The ``qml.shadows.shadow_expval`` transform has been deprecated. Instead, please use the
+ ``qml.shadow_expval`` measurement process.
+
+ - Deprecated in v0.39
+ - Will be removed in v0.40
+
+* ``qml.broadcast`` has been deprecated. Users should use ``for`` loops instead.
+
+ - Deprecated in v0.39
+ - Will be removed in v0.40
+
+* The ``qml.qinfo`` module has been deprecated. Please see the respective functions in the ``qml.math`` and ``qml.measurements``
+ modules instead.
+
+ - Deprecated in v0.39
+ - Will be removed in v0.40
+
 * ``Device``, ``QubitDevice``, and ``QutritDevice`` will no longer be imported top level in v0.40. They instead
  we be available as ``qml.devices.LegacyDevice``, ``qml.devices.QubitDevice``, and ``qml.devices.QutritDevice``
  respectively.
 
  - Deprecated top level access in v0.39
- - Top level access removed in v0.40
+ - Top level access will be removed in v0.40
 
-* `QNode.gradient_fn` is deprecated. Please use `QNode.diff_method` instead. `QNode.get_gradient_fn` can also be used to
+* ``QNode.gradient_fn`` is deprecated. Please use ``QNode.diff_method`` instead. ``QNode.get_gradient_fn`` can also be used to
  process the diff method.
 
  - Deprecated in v0.39
@@ -27,18 +50,21 @@ Pending deprecations
  - Deprecated in v0.38
  - Will be removed in v0.39
 
-* The functions ``qml.qinfo.classical_fisher`` and ``qml.qinfo.quantum_fisher`` are deprecated since they are being migrated
- to the ``qml.gradients`` module. Therefore, ``qml.gradients.classical_fisher`` and ``qml.gradients.quantum_fisher`` should be used instead.
-
- - Deprecated and Duplicated in v0.38
- - Will be removed in v0.39
-
 * The ``simplify`` argument in ``qml.Hamiltonian`` and ``qml.ops.LinearCombination`` is deprecated. 
  Instead, ``qml.simplify()`` can be called on the constructed operator.
 
  - Deprecated in v0.37
  - Will be removed in v0.39
 
+* The :class:`~pennylane.BasisStatePreparation` template is deprecated.
+ Instead, use :class:`~pennylane.BasisState`.
+
+* The ``QubitStateVector`` template is deprecated.
+ Instead, use ``StatePrep``.
+
+ - Deprecated in v0.39
+ - Will be removed in v0.40
+
 New operator arithmetic deprecations
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -83,6 +109,23 @@ Other deprecations
 Completed deprecation cycles
 ----------------------------
 
+* The ``simplify`` argument in ``qml.Hamiltonian`` and ``qml.ops.LinearCombination`` has been removed.
+ Instead, ``qml.simplify()`` can be called on the constructed operator.
+
+ - Deprecated in v0.37
+ - Removed in v0.39
+
+* The ``decomp_depth`` argument in ``qml.device`` is removed.
+
+ - Deprecated in v0.38
+ - Removed in v0.39
+
+* The functions ``qml.qinfo.classical_fisher`` and ``qml.qinfo.quantum_fisher`` have been removed and migrated to the ``qml.gradients``
+ module. Therefore, ``qml.gradients.classical_fisher`` and ``qml.gradients.quantum_fisher`` should be used instead.
+
+ - Deprecated in v0.38
+ - Removed in v0.39
+
 * All of the legacy devices (any with the name ``default.qubit.{autograd,torch,tf,jax,legacy}``) are removed. Use ``default.qubit`` instead,
  as it supports backpropagation for the many backends the legacy devices support.
 

doc/news/new_opmath.rst

@@ -245,10 +245,10 @@ To help identify a fix, select the option below that describes your situation.
  >>> qml.Hamiltonian([0.5], [X(0) @ X(1)])
  0.5 * (X(0) @ X(1))
 
- The API of :class:`~.ops.op_math.LinearCombination` is identical to that of :class:`~.Hamiltonian`. We can group observables or simplify upon initialization.
+ The API of :class:`~.ops.op_math.LinearCombination` is identical to that of :class:`~.Hamiltonian`. We can group observables upon initialization.
 
- >>> H1 = qml.Hamiltonian([0.5, 0.5, 0.5], [X(0) @ X(1), X(0), Y(0)], grouping_type="qwc", simplify=True)
- >>> H2 = qml.ops.LinearCombination([0.5, 0.5, 0.5], [X(0) @ X(1), X(0), Y(0)], grouping_type="qwc", simplify=True)
+ >>> H1 = qml.Hamiltonian([0.5, 0.5, 0.5], [X(0) @ X(1), X(0), Y(0)], grouping_type="qwc")
+ >>> H2 = qml.ops.LinearCombination([0.5, 0.5, 0.5], [X(0) @ X(1), X(0), Y(0)], grouping_type="qwc")
  >>> H1 == H2
  True
 

doc/releases/changelog-dev.md

@@ -10,6 +10,9 @@
  [(#6061)](https://github.com/PennyLaneAI/pennylane/pull/6061)
  [(#6258)](https://github.com/PennyLaneAI/pennylane/pull/6258)
 
+* PennyLane is now compatible with Jax 0.4.28.
+ [(#6255)](https://github.com/PennyLaneAI/pennylane/pull/6255)
+
 * `qml.qchem.excitations` now optionally returns fermionic operators.
  [(#6171)](https://github.com/PennyLaneAI/pennylane/pull/6171)
 
@@ -37,6 +40,9 @@
  `from pennylane.capture.primitives import *`.
  [(#6129)](https://github.com/PennyLaneAI/pennylane/pull/6129)
 
+* `FermiWord` class now has a method to apply anti-commutator relations.
+ [(#6196)](https://github.com/PennyLaneAI/pennylane/pull/6196)
+
 * `FermiWord` and `FermiSentence` classes now have methods to compute adjoints.
  [(#6166)](https://github.com/PennyLaneAI/pennylane/pull/6166)
 
@@ -51,12 +57,23 @@
  unique representation of the object.
  [(#6167)](https://github.com/PennyLaneAI/pennylane/pull/6167)
 
+* A `ReferenceQubit` is introduced for testing purposes and as a reference for future plugin development.
+ [(#6181)](https://github.com/PennyLaneAI/pennylane/pull/6181)
+
 * The `to_mat` methods for `FermiWord` and `FermiSentence` now optionally return
  a sparse matrix.
  [(#6173)](https://github.com/PennyLaneAI/pennylane/pull/6173)
 
 <h3>Breaking changes 💔</h3>
 
+* The `simplify` argument in `qml.Hamiltonian` and `qml.ops.LinearCombination` has been removed.
+ Instead, `qml.simplify()` can be called on the constructed operator.
+ [(#6279)](https://github.com/PennyLaneAI/pennylane/pull/6279)
+
+* The functions `qml.qinfo.classical_fisher` and `qml.qinfo.quantum_fisher` have been removed and migrated to the `qml.gradients`
+ module. Therefore, `qml.gradients.classical_fisher` and `qml.gradients.quantum_fisher` should be used instead.
+ [(#5911)](https://github.com/PennyLaneAI/pennylane/pull/5911)
+
 * Remove support for Python 3.9.
  [(#6223)](https://github.com/PennyLaneAI/pennylane/pull/6223)
 
@@ -81,12 +98,36 @@
  Please use `qml.transforms.split_non_commuting` instead.
  [(#6204)](https://github.com/PennyLaneAI/pennylane/pull/6204)
 
+* The `decomp_depth` keyword argument to `qml.device` is removed.
+ [(#6234)](https://github.com/PennyLaneAI/pennylane/pull/6234)
+
 * `Operator.expand` is now removed. Use `qml.tape.QuantumScript(op.deocomposition())` instead.
  [(#6227)](https://github.com/PennyLaneAI/pennylane/pull/6227)
 
 
 <h3>Deprecations 👋</h3>
 
+* The `qml.BasisStatePreparation` template is deprecated.
+ Instead, use `qml.BasisState`.
+ [(#6021)](https://github.com/PennyLaneAI/pennylane/pull/6021)
+
+* The `'ancilla'` argument for `qml.iterative_qpe` has been deprecated. Instead, use the `'aux_wire'` argument.
+ [(#6277)](https://github.com/PennyLaneAI/pennylane/pull/6277)
+
+* `qml.shadows.shadow_expval` has been deprecated. Instead, use the `qml.shadow_expval` measurement
+ process.
+ [(#6277)](https://github.com/PennyLaneAI/pennylane/pull/6277)
+
+* `qml.broadcast` has been deprecated. Please use `for` loops instead.
+ [(#6277)](https://github.com/PennyLaneAI/pennylane/pull/6277)
+
+* The `qml.QubitStateVector` template is deprecated. Instead, use `qml.StatePrep`.
+ [(#6172)](https://github.com/PennyLaneAI/pennylane/pull/6172)
+
+* The `qml.qinfo` module has been deprecated. Please see the respective functions in the `qml.math` and
+ `qml.measurements` modules instead.
+ [(#5911)](https://github.com/PennyLaneAI/pennylane/pull/5911)
+
 * `Device`, `QubitDevice`, and `QutritDevice` will no longer be accessible via top-level import in v0.40.
  They will still be accessible as `qml.devices.LegacyDevice`, `qml.devices.QubitDevice`, and `qml.devices.QutritDevice`
  respectively.
@@ -97,24 +138,27 @@
 
 <h3>Documentation 📝</h3>
 
+* Add `work_wires` parameter to `qml.MultiControlledX` docstring signature.
+ [(#6271)](https://github.com/PennyLaneAI/pennylane/pull/6271) 
+
 <h3>Bug fixes 🐛</h3>
 
 * Fix a bug where zero-valued JVPs were calculated wrongly in the presence of shot vectors.
  [(#6219)](https://github.com/PennyLaneAI/pennylane/pull/6219)
 
-* Fix `qml.PrepSelPrep` template to work with `torch`:
+* Fix `qml.PrepSelPrep` template to work with `torch`.
  [(#6191)](https://github.com/PennyLaneAI/pennylane/pull/6191)
 
 * Now `qml.equal` compares correctly `qml.PrepSelPrep` operators.
  [(#6182)](https://github.com/PennyLaneAI/pennylane/pull/6182)
 
-* The ``qml.QSVT`` template now orders the ``projector`` wires first and the ``UA`` wires second, which is the expected order of the decomposition.
+* The `qml.QSVT` template now orders the `projector` wires first and the `UA` wires second, which is the expected order of the decomposition.
  [(#6212)](https://github.com/PennyLaneAI/pennylane/pull/6212)
 
-* The ``qml.Qubitization`` template now orders the ``control`` wires first and the ``hamiltonian`` wires second, which is the expected according to other templates.
+* The `qml.Qubitization` template now orders the `control` wires first and the `hamiltonian` wires second, which is the expected according to other templates.
  [(#6229)](https://github.com/PennyLaneAI/pennylane/pull/6229)
 
-* The ``qml.FABLE`` template now returns the correct value when JIT is enabled.
+* The `qml.FABLE` template now returns the correct value when JIT is enabled.
  [(#6263)](https://github.com/PennyLaneAI/pennylane/pull/6263)
 
 * Fixes a bug where a circuit using the `autograd` interface sometimes returns nested values that are not of the `autograd` interface.
@@ -130,10 +174,12 @@ This release contains contributions from (in alphabetical order):
 Guillermo Alonso,
 Utkarsh Azad,
 Astral Cai,
+Isaac De Vlugt,
 Lillian M. A. Frederiksen,
 Pietropaolo Frisoni,
 Emiliano Godinez,
 Christina Lee,
 William Maxwell,
 Lee J. O'Riordan,
+Mudit Pandey,
 David Wierichs,

pennylane/_version.py

@@ -16,4 +16,4 @@
 Version number (major.minor.patch[-label])
 """
 
-__version__ = "0.39.0-dev16"
+__version__ = "0.39.0-dev18"

pennylane/devices/__init__.py

@@ -37,6 +37,7 @@
  _qubit_device
  _qutrit_device
  null_qubit
+ reference_qubit
  tests
 
 Next generation devices
@@ -58,6 +59,7 @@
  DefaultQubit
  DefaultTensor
  NullQubit
+ ReferenceQubit
  DefaultQutritMixed
  LegacyDeviceFacade
 
@@ -160,6 +162,7 @@ def execute(self, circuits, execution_config = qml.devices.DefaultExecutionConfi
 from .default_clifford import DefaultClifford
 from .default_tensor import DefaultTensor
 from .null_qubit import NullQubit
+from .reference_qubit import ReferenceQubit
 from .default_qutrit import DefaultQutrit
 from .default_qutrit_mixed import DefaultQutritMixed
 from ._legacy_device import Device as LegacyDevice

pennylane/devices/_qubit_device.py

@@ -1153,7 +1153,7 @@ def classical_shadow(self, obs, circuit):
  def shadow_expval(self, obs, circuit):
  r"""Compute expectation values using classical shadows in a differentiable manner.
 
- Please refer to :func:`~.pennylane.shadow_expval` for detailed documentation.
+ Please refer to :func:`~pennylane.shadow_expval` for detailed documentation.
 
  Args:
  obs (~.pennylane.measurements.ClassicalShadowMP): The classical shadow expectation

pennylane/devices/_qutrit_device.py

@@ -230,7 +230,7 @@ def classical_shadow(self, obs, circuit):
  def shadow_expval(self, obs, circuit):
  r"""Compute expectation values using classical shadows in a differentiable manner.
 
- Please refer to :func:`~.pennylane.shadow_expval` for detailed documentation.
+ Please refer to :func:`~pennylane.shadow_expval` for detailed documentation.
 
  .. seealso:: :func:`~pennylane.shadow_expval`
 

pennylane/devices/default_mixed.py

@@ -763,8 +763,9 @@ def execute(self, circuit, **kwargs):
  self.measured_wires = self.wires
  return super().execute(circuit, **kwargs)
  if isinstance(m, (VnEntropyMP, MutualInfoMP)):
- # VnEntropy, MutualInfo: Computed for the state prior to measurement. So, readout
- # error need not be applied on the corresponding device wires.
+ # VnEntropy, MutualInfo: Computed for the state
+ # prior to measurement. So, readout error need not be applied to the
+ # corresponding device wires.
  continue
  wires_list.append(m.wires)
  self.measured_wires = qml.wires.Wires.all_wires(wires_list)