Pennylane-lightning

Improvements

* Use the `adjoint` gate parameter to apply `qml.Adjoint` operations instead of matrix methods in `lightning.qubit`.
[(632)](https://github.com/PennyLaneAI/pennylane-lightning/pull/632)

Bug fixes

* Fix `qml.Adjoint` support in `lightning.gpu` and `lightning.kokkos`.
[(632)](https://github.com/PennyLaneAI/pennylane-lightning/pull/632)

* Fix finite shots support in `lightning.qubit`, `lightning.gpu` and `lightning.kokkos`. The bug would impact calculations with measurements on observables with non-trivial diagonalizing gates and calculations with shot vectors.
[(632)](https://github.com/PennyLaneAI/pennylane-lightning/pull/632)

Contributors

This release contains contributions from (in alphabetical order):

Vincent Michaud-Rioux

New features since last release

* All backends now support `GlobalPhase` and `C(GlobalPhase)` in forward pass.
[(579)](https://github.com/PennyLaneAI/pennylane-lightning/pull/579)

* Add Hermitian observable support for shot-noise measurement and Lapack support.
[(569)](https://github.com/PennyLaneAI/pennylane-lightning/pull/569)

Breaking changes

* Migrate `lightning.gpu` to CUDA 12.
[(606)](https://github.com/PennyLaneAI/pennylane-lightning/pull/606)

Improvements

* Expand error values and strings returned from CUDA libraries.
[(617)](https://github.com/PennyLaneAI/pennylane-lightning/pull/617)

* `C(MultiRZ)` and `C(Rot)` gates are natively supported (with `LM` kernels).
[(614)](https://github.com/PennyLaneAI/pennylane-lightning/pull/614)

* Add adjoint support for `GlobalPhase` in Lightning-GPU and Lightning-Kokkos.
[(615)](https://github.com/PennyLaneAI/pennylane-lightning/pull/615)

* Lower the overheads of Windows CI tests.
[(610)](https://github.com/PennyLaneAI/pennylane-lightning/pull/610)

* Decouple LightningQubit memory ownership from numpy and migrate it to Lightning-Qubit managed state-vector class.
[(601)](https://github.com/PennyLaneAI/pennylane-lightning/pull/601)

* Expand support for Projector observables on Lightning-Kokkos.
[(601)](https://github.com/PennyLaneAI/pennylane-lightning/pull/601)

* Split Docker build cron job into two jobs: master and latest. This is mainly for reporting in the `plugin-test-matrix` repo.
[(600)](https://github.com/PennyLaneAI/pennylane-lightning/pull/600)

* The `BlockEncode` operation from PennyLane is now supported on all Lightning devices.
[(599)](https://github.com/PennyLaneAI/pennylane-lightning/pull/599)

* OpenMP acceleration can now be enabled at compile time for all `lightning.qubit` gate kernels using the "-DLQ_ENABLE_KERNEL_OMP=1" CMake argument.
[(510)](https://github.com/PennyLaneAI/pennylane-lightning/pull/510)

* Enable building Docker images for any branch or tag. Set the Docker build cron job to build images for the latest release and `master`.
[(598)](https://github.com/PennyLaneAI/pennylane-lightning/pull/598)

* Enable choosing the PennyLane-Lightning version and disabling push to Docker Hub in the Docker build workflow. Add a cron job calling the Docker build workflow.
[(597)](https://github.com/PennyLaneAI/pennylane-lightning/pull/597)

* Pull Kokkos v4.2.00 from the official Kokkos repository to test Lightning-Kokkos with the CUDA backend.
[(596)](https://github.com/PennyLaneAI/pennylane-lightning/pull/596)

* Remove deprecated MeasurementProcess.name.
[(605)](https://github.com/PennyLaneAI/pennylane-lightning/pull/605)

Documentation

* Update requirements to build the documentation.
[(594)](https://github.com/PennyLaneAI/pennylane-lightning/pull/594)

Bug fixes

* Downgrade auditwheel due to changes with library exclusion list.
[(620)](https://github.com/PennyLaneAI/pennylane-lightning/pull/620)

* List `GlobalPhase` gate in each device's TOML file.
[(615)](https://github.com/PennyLaneAI/pennylane-lightning/pull/615)

* Lightning-GPU's gate cache failed to distinguish between certain gates.
For example, `MultiControlledX([0, 1, 2], "111")` and `MultiControlledX([0, 2], "00")` were applied as the same operation.
This could happen with (at least) the following gates: `QubitUnitary`,`ControlledQubitUnitary`,`MultiControlledX`,`DiagonalQubitUnitary`,`PSWAP`,`OrbitalRotation`.
[(579)](https://github.com/PennyLaneAI/pennylane-lightning/pull/579)

* Ensure the stopping condition decompositions are respected for larger templated QFT and Grover operators.
[(609)](https://github.com/PennyLaneAI/pennylane-lightning/pull/609)

* Move concurrency group specifications from reusable Docker build workflow to the root workflows.
[(604)](https://github.com/PennyLaneAI/pennylane-lightning/pull/604)

* Fix `lightning-kokkos-cuda` Docker build and add CI workflow to build images and push to Docker Hub.
[(593)](https://github.com/PennyLaneAI/pennylane-lightning/pull/593)

* Update jax.config imports.
[(619)](https://github.com/PennyLaneAI/pennylane-lightning/pull/619)

* Fix apply state vector when using a Lightning handle.
[(622)](https://github.com/PennyLaneAI/pennylane-lightning/pull/622)

* Pinning Pytest to a version compatible with Flaky.
[(624)](https://github.com/PennyLaneAI/pennylane-lightning/pull/624)

Contributors

This release contains contributions from (in alphabetical order):

Amintor Dusko, David Ittah, Vincent Michaud-Rioux, Lee J. O'Riordan, Shuli Shu, Matthew Silverman

New features since last release

* Support added for Python 3.12 wheel builds. [(541)](https://github.com/PennyLaneAI/pennylane-lightning/pull/541)

* Lightning-Qubit support arbitrary controlled gates (any wires and any control values). The kernels are implemented in the `LM` module. [(576)](https://github.com/PennyLaneAI/pennylane-lightning/pull/576)

* Shot-noise related methods now accommodate observable objects with arbitrary eigenvalues. Add a Kronecker product method for two diagonal matrices. [(570)](https://github.com/PennyLaneAI/pennylane-lightning/pull/570)

* Add shot-noise support for probs in the C++ layer. Probabilities are calculated from generated samples. All Lightning backends support this feature. Please note that target wires should be sorted in ascending manner. [(568)](https://github.com/PennyLaneAI/pennylane-lightning/pull/568)

* Add `LM` kernels to apply arbitrary controlled operations efficiently. [(516)](https://github.com/PennyLaneAI/pennylane-lightning/pull/516)

* Add shots support for variance value, probs, sample, counts calculation for given observables (`NamedObs`, `TensorProd` and `Hamiltonian`) based on Pauli words, `Identity` and `Hadamard` in the C++ layer. All Lightning backends support this support feature. [(561)](https://github.com/PennyLaneAI/pennylane-lightning/pull/561)

* Add shots support for expectation value calculation for given observables (`NamedObs`, `TensorProd` and `Hamiltonian`) based on Pauli words, `Identity` and `Hadamard` in the C++ layer by adding `measure_with_samples` to the measurement interface. All Lightning backends support this support feature. [(556)](https://github.com/PennyLaneAI/pennylane-lightning/pull/556)

* `qml.QubitUnitary` operators can be included in a circuit differentiated with the adjoint method. Lightning handles circuits with arbitrary non-differentiable `qml.QubitUnitary` operators. 1,2-qubit `qml.QubitUnitary` operators with differentiable parameters can be differentiated using decomposition. [(540)](https://github.com/PennyLaneAI/pennylane-lightning/pull/540)

Breaking changes

* Set the default version of Kokkos to 4.2.00 throughout the project (CMake, CI, etc.) [(578)](https://github.com/PennyLaneAI/pennylane-lightning/pull/578)

* Overload `applyOperation` with a fifth `matrix` argument to all state vector classes to support arbitrary operations in `AdjointJacobianBase`. [(540)](https://github.com/PennyLaneAI/pennylane-lightning/pull/540)

Improvements

* Ensure aligned memory used for numpy arrays with state-vector without reallocations. [(572)](https://github.com/PennyLaneAI/pennylane-lightning/pull/572)

* Unify error messages of shot measurement related unsupported observables to better Catalyst. [(577)](https://github.com/PennyLaneAI/pennylane-lightning/pull/577)

* Add configuration files to improve compatibility with Catalyst. [(566)](https://github.com/PennyLaneAI/pennylane-lightning/pull/566)

* Refactor shot-noise related methods of MeasurementsBase class in the C++ layer and eigenvalues are not limited to `1` and `-1`. Add `getObs()` method to Observables class. Refactor `applyInPlaceShots` to allow users to get eigenvalues of Observables object. Deprecated `_preprocess_state` method in `MeasurementsBase` class for safer use of the `LightningQubitRaw` backend. [(570)](https://github.com/PennyLaneAI/pennylane-lightning/pull/570)

* Modify `setup.py` to use backend-specific build directory (`f"build_{backend}"`) to accelerate rebuilding backends in alternation. [(540)](https://github.com/PennyLaneAI/pennylane-lightning/pull/540)

* Update Dockerfile and rewrite the `build-wheel-lightning-gpu` stage to build Lightning-GPU from the `pennylane-lightning` monorepo. [(539)](https://github.com/PennyLaneAI/pennylane-lightning/pull/539)

* Add the MPI test CI workflows of Lightning-GPU in compatibility cron jobs. [(536)](https://github.com/PennyLaneAI/pennylane-lightning/pull/536)

* Add MPI synchronization in places to safely handle communicated data. [(538)](https://github.com/PennyLaneAI/pennylane-lightning/pull/538)

* Add release option in compatibility cron jobs to test the release candidates of PennyLane and the Lightning plugins against one another. [(531)](https://github.com/PennyLaneAI/pennylane-lightning/pull/531)

* Add GPU workflows in compatibility cron jobs to test Lightning-GPU and Lightning-Kokkos with the Kokkos CUDA backend. [(528)](https://github.com/PennyLaneAI/pennylane-lightning/pull/528)

Documentation

* Fixed a small typo in the documentation page for the PennyLane-Lightning GPU device. [(563)](https://github.com/PennyLaneAI/pennylane-lightning/pull/563)

* Add OpenGraph social preview for Lightning docs. [(574)](https://github.com/PennyLaneAI/pennylane-lightning/pull/574)

Bug fixes

* Fix CodeCov file contention issue when uploading data from many workloads. [(584)](https://github.com/PennyLaneAI/pennylane-lightning/pull/584)

* Ensure the `lightning.gpu` intermediate wheel builds are uploaded to TestPyPI. [(575)](https://github.com/PennyLaneAI/pennylane-lightning/pull/575)

* Allow support for newer clang-tidy versions on non-x86_64 platforms. [(567)](https://github.com/PennyLaneAI/pennylane-lightning/pull/567)

* Do not run C++ tests when testing for compatibility with PennyLane, hence fixing plugin-matrix failures. Fix Lightning-GPU workflow trigger. [(571)](https://github.com/PennyLaneAI/pennylane-lightning/pull/571)

* Revert single-node multi-GPU batching behaviour to match https://github.com/PennyLaneAI/pennylane-lightning-gpu/pull/27. [(#564)](https://github.com/PennyLaneAI/pennylane-lightning/pull/564)

* Move deprecated `stateprep` `QuantumScript` argument into the operation list in `mpitests/test_adjoint_jacobian.py`. [(540)](https://github.com/PennyLaneAI/pennylane-lightning/pull/540)

* Fix MPI Python unit tests for the adjoint method. [(538)](https://github.com/PennyLaneAI/pennylane-lightning/pull/538)

* Fix the issue with assigning kernels to ops before registering kernels on macOS. [(582)](https://github.com/PennyLaneAI/pennylane-lightning/pull/582)

* Update `MANIFEST.in` to include device config files and `CHANGELOG.md`. [(585)](https://github.com/PennyLaneAI/pennylane-lightning/pull/585)

Contributors

This release contains contributions from (in alphabetical order):

Ali Asadi, Isaac De Vlugt, Amintor Dusko, Vincent Michaud-Rioux, Erick Ochoa Lopez, Lee James O'Riordan, Shuli Shu

New features since last release

* pip-installed CUDA runtime libraries can now be accessed from a virtualenv. (543 )

Bug fixes

* The pybind11 compiled module RPATH linkage has been restored to pre-0.33 behaviour. (543 )

Contributors

This release contains contributions from (in alphabetical order):

Lee J. O'Riordan

New features since last release

* Add documentation updates for the `lightning_gpu` backend. (525)

* Add `SparseHamiltonian` support for Lightning-Qubit and Lightning-GPU. (526)

* Add `SparseHamiltonian` support for Lightning-Kokkos. (527)

* Integrate python/pybind layer of distributed Lightning-GPU into the Lightning monorepo with python unit tests. (518)

* Integrate the distributed C++ backend of Lightning-GPU into the Lightning monorepo. (514)

* Integrate Lightning-GPU into the Lightning monorepo. The new backend is named `lightning_gpu` and includes all single-GPU features. (499)

* Build Linux wheels for Lightning-GPU (CUDA-11). (517)

* Add `Dockerfile` in `docker` and `make docker` workflow in `Makefile`. The Docker images and documentation are available on [DockerHub](https://hub.docker.com/repository/docker/pennylaneai/pennylane). (#496)

* Add mid-circuit state preparation operation tests. (495)

Improvements

* Improve Python testing for Lightning-GPU (+MPI) by adding jobs in Actions files and adding Python tests to increase code coverage. (522)

* Add support for `pip install pennylane-lightning[kokkos]` for the OpenMP backend. (515)

* Update `setup.py` to allow for multi-package co-existence. The `PennyLane_Lightning` package now is the responsible for the core functionality, and will be depended upon by all other extensions. (504)

* Redesign Lightning-Kokkos `StateVectorKokkos` class to use Kokkos `RangePolicy` together with special functors in `applyMultiQubitOp` to apply 1- to 4-wire generic unitary gates. For more than 4 wires, the general implementation using Kokkos `TeamPolicy` is employed to yield the best all-around performance. (490)

* Redesign Lightning-Kokkos `Measurements` class to use Kokkos `RangePolicy` together with special functors to obtain the expectation value of 1- to 4-wire generic unitary gates. For more than 4 wires, the general implementation using Kokkos `TeamPolicy` is employed to yield the best all-around performance. (489)

* Add tests to increase Lightning-Kokkos coverage. (485)

* Add memory locality tag reporting and adjoint diff dispatch for `lightning.qubit` statevector classes. (492)

* Add support for dependent external packages to C++ core. (482)

* Add support for building multiple backend simulators. (497)

Breaking changes

* Add `tests_gpu.yml` workflow to test the Lightning-Kokkos backend with CUDA-12. (494)

* Implement `LM::GeneratorDoubleExcitation`, `LM::GeneratorDoubleExcitationMinus`, `LM::GeneratorDoubleExcitationPlus` kernels. Lightning-Qubit default kernels are now strictly from the `LM` implementation, which requires less memory and is faster for large state vectors. (512)

* Add workflows validating compatibility between PennyLane and Lightning's most recent stable releases and development (latest) versions. (507) (498)

* Introduce `timeout-minutes` in various workflows, mainly to avoid Windows builds hanging for several hours. (503)

* Cast integral-valued arrays to the device's complex type on entry in `_preprocess_state_vector` to ensure the state is correctly represented with floating-point numbers. (501)

* Update `DefaultQubit` to `DefaultQubitLegacy` on Lightning fallback. (500)

* Enums defined in `GateOperation.hpp` start at `1` (previously `0`). `::BEGIN` is introduced in a few places where it was assumed `0` accordingly. (485) `::BEGIN` was later reverted to `0`, keeping the rest of the changes, to fix a compatibility issue with [Catalyst](https://docs.pennylane.ai/projects/catalyst/en/stable/). (#521)

* Enable pre-commit hooks to format all Python files and linting of all Python source files. (485)

Bug fixes

* Re-add support for `pip install pennylane-lightning[gpu]`. (515)

* Switch most Lightning-Qubit default kernels to `LM`. Add `LM::multiQubitOp` tests, failing when targeting out-of-order wires clustered close to `num_qubits-1`. Fix the `LM::multiQubitOp` kernel implementation by introducing a generic `revWireParity` routine and replacing the `bitswap`-based implementation. Mimic the changes fixing the corresponding `multiQubitOp` and `expval` functors in Lightning-Kokkos. (511)

* Fix RTD builds by removing unsupported `system_packages` configuration option. (491)

Contributors

This release contains contributions from (in alphabetical order):

Ali Asadi, Amintor Dusko, Vincent Michaud-Rioux, Lee J. O'Riordan, Shuli Shu

Improvements

* Refactor LKokkos `Measurements` class to use (fast) specialized functors whenever possible. [(481)](https://github.com/PennyLaneAI/pennylane-lightning/pull/481)

* Merge Lightning Qubit and Lightning Kokkos backends in the new repository. [(472)](https://github.com/PennyLaneAI/pennylane-lightning/pull/472)

New features since last release

* The `lightning_kokkos` backend supports Nvidia GPU execution (with Kokkos v4 and CUDA v12). [(477)](https://github.com/PennyLaneAI/pennylane-lightning/pull/477)

* Complete overhaul of repository structure to facilitate integration of multiple backends. Refactoring efforts we directed to improve development performance, and code reuse and decrease overall overhead to propagate changes through backends. The new C++ modular build strategy allows faster test builds restricted to a module. Update CI/CD actions concurrency strategy. Change the minimal Python version to 3.9. [(472)](https://github.com/PennyLaneAI/pennylane-lightning/pull/472)

* Wheels are built with native support for sparse Hamiltonians. [(470)](https://github.com/PennyLaneAI/pennylane-lightning/pull/470)

* Add native support to sparse Hamiltonians in the absence of Kokkos & Kokkos-kernels. [(465)](https://github.com/PennyLaneAI/pennylane-lightning/pull/465)

Breaking changes

* Rename `QubitStateVector` to `StatePrep` in the `LightningQubit` and `LightningKokkos` classes. [(486)](https://github.com/PennyLaneAI/pennylane-lightning/pull/486)

* Modify `adjointJacobian` methods to accept a (maybe unused) reference `StateVectorT`, allowing device-backed simulators to directly access state vector data for adjoint differentiation instead of copying it back-and-forth into `JacobianData` (host memory). [(477)](https://github.com/PennyLaneAI/pennylane-lightning/pull/477)

Documentation

* Integrated new unified docs for Lightning Kokkos and Lightning Qubit packages. [(473)](https://github.com/PennyLaneAI/pennylane-lightning/pull/473)

Bug fixes

* Ensure PennyLane has an `active_return` attribute before calling it. [(483)](https://github.com/PennyLaneAI/pennylane-lightning/pull/483)

* Do no import `sqrt2_v` from `<numbers>` in `Util.hpp` to resolve issue with Lightning-GPU builds. [(479)](https://github.com/PennyLaneAI/pennylane-lightning/pull/479)

* Update the CMake internal references to enable sub-project compilation with affecting the parent package. [(478)](https://github.com/PennyLaneAI/pennylane-lightning/pull/478)

* `apply` no longer mutates the inputted list of operations. [(474)](https://github.com/PennyLaneAI/pennylane-lightning/pull/474)

Contributors

This release contains contributions from (in alphabetical order):

Amintor Dusko, Christina Lee, Vincent Michaud-Rioux, Lee J. O'Riordan