Pennylane-lightning

Improvements

* Remove deprecated `set-output` commands from workflow files.
[(437)](https://github.com/PennyLaneAI/pennylane-lightning/pull/437)

* Lightning wheels are now checked with `twine check` post-creation for PyPI compatibility.
[(430)](https://github.com/PennyLaneAI/pennylane-lightning/pull/430)

* Lightning has been made compatible with the change in return types specification.
[(427)](https://github.com/PennyLaneAI/pennylane-lightning/pull/427)

* Lightning is compatible with clang-tidy version 16.
[(429)](https://github.com/PennyLaneAI/pennylane-lightning/pull/429)

Contributors

This release contains contributions from (in alphabetical order):

Christina Lee, Vincent Michaud-Rioux, Lee James O'Riordan, Chae-Yeun Park, Matthew Silverman

New features since last release

* Add Exact Tensor Network (TN) C++ backend to Lightning-Tensor. [(977)](https://github.com/PennyLaneAI/pennylane-lightning/pull/977)

* Add native N-controlled generators and adjoint support to `lightning.gpu`'s single-GPU backend. [(970)](https://github.com/PennyLaneAI/pennylane-lightning/pull/970)

* Add a Catalyst-specific wrapping class for Lightning-Qubit. [(960)](https://github.com/PennyLaneAI/pennylane-lightning/pull/960) [(#999)](https://github.com/PennyLaneAI/pennylane-lightning/pull/999)

* Add native N-controlled gate/matrix operations and adjoint support to `lightning.kokkos`. [(950)](https://github.com/PennyLaneAI/pennylane-lightning/pull/950)

* Add native N-controlled gates support to `lightning.gpu`'s single-GPU backend. [(938)](https://github.com/PennyLaneAI/pennylane-lightning/pull/938)

Breaking changes

* Remove all instances of the legacy operator arithmetic (the `Hamiltonian` and `Tensor` deprecated classes in PennyLane). [(994)](https://github.com/PennyLaneAI/pennylane-lightning/pull/994) [(#997)](https://github.com/PennyLaneAI/pennylane-lightning/pull/997)

* Remove all instances of `qml.QubitStateVector` as deprecated in PennyLane. [(985)](https://github.com/PennyLaneAI/pennylane-lightning/pull/985)

Improvements

* Add CI wheels checks for `aarch64` wheels of Lightning-GPU and Lightning-Tensor. [(1031)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1031)

* Replace the `dummy_tensor_update` method with the `cutensornetStateCaptureMPS` API to ensure that applying gates is allowed after the `cutensornetStateCompute` call. [(1028)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1028)

* Add unit tests for measurement with shots for Lightning-Tensor (`method="tn"`). [(1027)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1027)

* Add CUDA dependencies to Lightning-GPU and Lightning-Tensor Python wheels. [(1025)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1025)

* Update the python layer UI of Lightning-Tensor. [(1022)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1022)

* Catalyst device interfaces support dynamic shots, and no longer parses the device init op's attribute dictionary for a static shots literal. [(1017)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1017)

* Update the logic for enabling `grad_on_execution` during device execution. [(1016)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1016)

* Reduce flaky test and increase test shots count. [(1015)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1015)

* Add Python bindings for Lightning-Tensor (Exact Tensor Network). [(1014)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1014)

* Reverse Lightning-Qubit generators vector insertion order. [(1009)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1009)

* Update Kokkos version support to 4.5. [(1007)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1007)

* Enable N-controlled gate and matrix support to `lightning.gpu` simulator for Catalyst. [(1005)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1005)

* Generalize seeding mechanism for all measurements. [(1003)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1003)

* `lightning.qubit`, `lightning.gpu`, and `lightning.kokkos` now define
the `eval_jaxpr` method for integration with the experimental
capture project. [(1002)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1002)

* Update Kokkos version support to 4.4.1 and enable Lightning-Kokkos[CUDA] C++ tests on CI. [(1000)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1000)

* Add C++ unit tests for Lightning-Tensor (Exact Tensor Network). [(998)](https://github.com/PennyLaneAI/pennylane-lightning/pull/998)

* Add native BLAS support to the C++ layer via dynamic `scipy-openblas32` loading. [(995)](https://github.com/PennyLaneAI/pennylane-lightning/pull/995)

* Update installation instruction for Lightning-GPU-MPI to explicitly ask users to add `path/to/libmpi.so` to the `LD_LIBRARY_PATH`. Update the runtime error message to ensure users know how to fix. [(993)](https://github.com/PennyLaneAI/pennylane-lightning/pull/993)

* Update the Lightning TOML files for the devices to use the new schema for declaring device capabilities. [(988)](https://github.com/PennyLaneAI/pennylane-lightning/pull/988)

* Optimize lightning.tensor by adding direct MPS sites data set with `qml.MPSPrep`. [(983)](https://github.com/PennyLaneAI/pennylane-lightning/pull/983)

* Unify excitation gates memory layout to row-major for both Lightning-GPU and Lightning-Tensor. [(959)](https://github.com/PennyLaneAI/pennylane-lightning/pull/959)

* Update the Lightning-Kokkos CUDA backend for compatibility with Catalyst. [(942)](https://github.com/PennyLaneAI/pennylane-lightning/pull/942)

Documentation

* Update and improve `README.rst` and documentations. [(1035)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1035)

* Add the exact tensor network to the `README.rst` and update link to `HIP`. [(1034)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1034)

* Add the exact tensor network to the Lightning-Tensor docs. [(1021)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1021)

* Update Lightning-Tensor installation docs and usage suggestions. [(979)](https://github.com/PennyLaneAI/pennylane-lightning/pull/979)

Bug fixes

* Fix Python CUDA dependencies by adding path to `nvidia/nvjitlink/lib` to RPATH. [(1031)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1031)

* Add `RTLD_NODELETE` flag to `dlopen` in order to mitigate the segfault issues for arm64-macos Catalyst support. [(1030)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1030)

* Set RPATH with `loader_path` instead of `$ORIGIN` for macOS. [(1029)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1029)

* Update CUDA version to 12.4 for GPU tests on CI. [(1023)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1023)

* Pin `jax[cpu]==0.4.28` for compatibility with PennyLane and Catalyst. [(1019)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1019)

* Fix Lightning-Kokkos `[[maybe_unused]]` and `exp2` errors with hipcc. [(1018)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1018)

* Fix Lightning-Kokkos editable mode path. [(1010)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1010)

* Fix the missing `ninja` in Linux AARCH64 wheels recipe. [(1007)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1007)

* Fix version switch condition the GPU workflow tests for LGPU and LKokkos. [(1006)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1006)

* Fix issue with `lightning.gpu` Rot operation with adjoint. [(1004)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1004)

* Fix the Lightning-Kokkos[CUDA] C++ API `cudaFree` segfaults in `applyMatrix`. [(1000)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1000)

* Fix issue with adjoint-jacobian of adjoint ops. [(996)](https://github.com/PennyLaneAI/pennylane-lightning/pull/996)

* Fix the `upload-pypi` token issues for Linux and MacOS (x86_64 & AARCH64) wheels. [(989)](https://github.com/PennyLaneAI/pennylane-lightning/pull/989)

* Fix Pennylane dependency branch (`v0.39_rc0` to `master`). [(984)](https://github.com/PennyLaneAI/pennylane-lightning/pull/984)

* Fix PTM stable latest. Removing FIXME patch for v0.39. [(982)](https://github.com/PennyLaneAI/pennylane-lightning/pull/982)

Contributors

This release contains contributions from (in alphabetical order):

Ali Asadi, Astral Cai, Amintor Dusko, Christina Lee, Joseph Lee, Anton Naim Ibrahim, Luis Alfredo Nuñez Meneses, Andrija Paurevic, Shuli Shu, Raul Torres, Haochen Paul Wang

New features since last release

* Add support for out-of-order `qml.probs` in `lightning.gpu`. [(941)](https://github.com/PennyLaneAI/pennylane-lightning/pull/941)

* Add mid-circuit measurements support to `lightning.gpu`'s single-GPU backend. [(931)](https://github.com/PennyLaneAI/pennylane-lightning/pull/931)

* Integrate Lightning-GPU with Catalyst so that hybrid programs can be seamlessly QJIT-compiled and executed on this device following `pip install pennylane-lightning-gpu`. [(928)](https://github.com/PennyLaneAI/pennylane-lightning/pull/928)

* Add `qml.Projector` observable support via diagonalization to Lightning-GPU. [(894)](https://github.com/PennyLaneAI/pennylane-lightning/pull/894)

* Add 1-target wire controlled gate support to `lightning.tensor`. Note that `cutensornet` only supports 1-target wire controlled gate as of `v24.08`. A controlled gate with more than 1 target wire should be converted to dense matrix. [(880)](https://github.com/PennyLaneAI/pennylane-lightning/pull/880)

* Build and upload Lightning-Tensor wheels (x86_64, AARCH64) to PyPI. [(862)](https://github.com/PennyLaneAI/pennylane-lightning/pull/862) [(#905)](https://github.com/PennyLaneAI/pennylane-lightning/pull/905)

* Add Matrix Product Operator (MPO) for all gates support to `lightning.tensor`. Note current C++ implementation only works for MPO sites data provided by users. [(859)](https://github.com/PennyLaneAI/pennylane-lightning/pull/859)

* Add shots measurement support to `lightning.tensor`. [(852)](https://github.com/PennyLaneAI/pennylane-lightning/pull/852)

* Lightning-GPU and Lightning-Kokkos migrated to the new device API. [(853)](https://github.com/PennyLaneAI/pennylane-lightning/pull/853) [(#810)](https://github.com/PennyLaneAI/pennylane-lightning/pull/810)

Breaking changes

* Update MacOS wheel build to 13.0 for X86_64 and ARM due to the deprecation of MacOS-12 CI runners. [(969)](https://github.com/PennyLaneAI/pennylane-lightning/pull/969)

* Deprecate `initSV()` and add `resetStateVector()` from the C++ API Lightning-GPU. This is to remove the `reset_state` additional call in the Python layer. [(933)](https://github.com/PennyLaneAI/pennylane-lightning/pull/933)

* Deprecate PI gates implementation in Lightning-Qubit. The PI gates were the first implementation of gate kernels in `lightning.qubit` using pre-computed indices, prior to the development of LM (less memory) and AVX kernels. This deprecation is in favour of reducing compilation time and ensuring that Lightning-Qubit only relies on LM kernels in the dynamic dispatcher across all platforms. [(925)](https://github.com/PennyLaneAI/pennylane-lightning/pull/925)

* Remove PowerPC wheel build recipe for Lightning-Qubit. [(902)](https://github.com/PennyLaneAI/pennylane-lightning/pull/902)

* Update MacOS wheel builds to require Monterey (12.0) or greater for x86_64 and ARM. This was required to update Pybind11 to the latest release (2.13.5) for enabling Numpy 2.0 support in Lightning. [(901)](https://github.com/PennyLaneAI/pennylane-lightning/pull/901)

* Remove support for Python 3.9 for all Lightning simulators. [(891)](https://github.com/PennyLaneAI/pennylane-lightning/pull/891)

Improvements

* Update the `lightning.tensor` Python layer unit tests, as `lightning.tensor` cannot be cleaned up like other state-vector devices because the data is attached to the graph. It is recommended to use one device per circuit for `lightning.tensor`. [(971)](https://github.com/PennyLaneAI/pennylane-lightning/pull/971)

* Add joint check for the N-controlled wires support in `lightning.qubit`. [(949)](https://github.com/PennyLaneAI/pennylane-lightning/pull/949)

* Optimize `GlobalPhase` and `C(GlobalPhase)` gate implementation in `lightning.gpu`. [(946)](https://github.com/PennyLaneAI/pennylane-lightning/pull/946)

* Add missing `liblightning_kokkos_catalyst.so` when building Lightning-Kokkos in editable installation. [(945)](https://github.com/PennyLaneAI/pennylane-lightning/pull/945)

* Optimize the cartesian product to reduce the amount of memory necessary to set the `StatePrep` in Lightning-Tensor. [(943)](https://github.com/PennyLaneAI/pennylane-lightning/pull/943)

* Update the `qml.probs` data-return in Lightning-GPU C++ API to align with other state-vector devices. [(941)](https://github.com/PennyLaneAI/pennylane-lightning/pull/941)

* Add zero-state initialization to both `StateVectorCudaManaged` and `StateVectorCudaMPI` constructors to remove the `reset_state` in the Python layer ctor and refactor `setBasisState(state, wires)` in the C++ API. [(933)](https://github.com/PennyLaneAI/pennylane-lightning/pull/933)

* Add `setStateVector(state, wire)` support to the Lightning-GPU C++ API. [(930)](https://github.com/PennyLaneAI/pennylane-lightning/pull/930)

* The `generate_samples` methods of `lightning.qubit` and `lightning.kokkos` can now take in a seed number to make the generated samples deterministic. This can be useful when, among other things, fixing flaky tests in CI. [(927)](https://github.com/PennyLaneAI/pennylane-lightning/pull/927)

* Remove dynamic decomposition rules for all Lightning devices. [(926)](https://github.com/PennyLaneAI/pennylane-lightning/pull/926)

* Always decompose `qml.QFT` in all Lightning devices. [(924)](https://github.com/PennyLaneAI/pennylane-lightning/pull/924)

* Uniform Python format to adhere PennyLane style. [(924)](https://github.com/PennyLaneAI/pennylane-lightning/pull/924)

* Add the `ci:use-gpu-runner` GitHub label to `lightning.kokkos` GPU Testing CIs. [(916)](https://github.com/PennyLaneAI/pennylane-lightning/pull/916)

* Update the test suite to remove deprecated code. [(912)](https://github.com/PennyLaneAI/pennylane-lightning/pull/912)

* Merge `lightning.gpu` and `lightning.tensor` GPU tests in single Python and C++ CIs controlled by the `ci:use-gpu-runner` label. [(911)](https://github.com/PennyLaneAI/pennylane-lightning/pull/911)

* Skip the compilation of Lightning simulators and development requirements to boost the build of public docs up to 5x. [(904)](https://github.com/PennyLaneAI/pennylane-lightning/pull/904)

* Build Lightning wheels in `Release` mode to reduce the binary sizes. [(903)](https://github.com/PennyLaneAI/pennylane-lightning/pull/903)

* Update Pybind11 to 2.13.5. [(901)](https://github.com/PennyLaneAI/pennylane-lightning/pull/901)

* Migrate wheels artifacts to v4. [(893)](https://github.com/PennyLaneAI/pennylane-lightning/pull/893)

* Update GitHub actions in response to a high-severity vulnerability. [(887)](https://github.com/PennyLaneAI/pennylane-lightning/pull/887)

* Optimize and simplify controlled kernels in Lightning-Qubit. [(882)](https://github.com/PennyLaneAI/pennylane-lightning/pull/882)

* Optimize gate cache recording for Lightning-Tensor C++ API. [(879)](https://github.com/PennyLaneAI/pennylane-lightning/pull/879)

* Unify Lightning-Kokkos and Lightning-Qubit devices under a Lightning-Base abstracted class. [(876)](https://github.com/PennyLaneAI/pennylane-lightning/pull/876)

* Smarter defaults for the `split_obs` argument in the serializer. The serializer splits linear combinations into chunks instead of all their terms. [(873)](https://github.com/PennyLaneAI/pennylane-lightning/pull/873/)

* Prefer `tomlkit` over `toml` for building Lightning wheels, and choose `tomli` and `tomllib` over `toml` when installing the package. [(857)](https://github.com/PennyLaneAI/pennylane-lightning/pull/857)

* Lightning-Kokkos gains native support for the `PauliRot` gate. [(855)](https://github.com/PennyLaneAI/pennylane-lightning/pull/855)

Documentation

* Update Lightning-Tensor installation docs and usage suggestions. [(971)](https://github.com/PennyLaneAI/pennylane-lightning/pull/971) [(#972)](https://github.com/PennyLaneAI/pennylane-lightning/pull/972)

* Update `README.rst` installation instructions for `lightning.gpu` and `lightning.tensor`. [(957)](https://github.com/PennyLaneAI/pennylane-lightning/pull/957)

* Update `lightning.tensor` documentation to include all the new features added since pull request 756. The new features are: 1. Finite-shot measurements; 2. Expval-base quantities; 3. Support for `qml.state()` and `qml.stateprep()`; 4. Support for all gates support via Matrix Product Operator (MPO). [(909)](https://github.com/PennyLaneAI/pennylane-lightning/pull/909)

Bug fixes

* Fix Lightning Kokkos test_device for `kokkos_args` fail for MacOS due to `np.complex256` [(974)](https://github.com/PennyLaneAI/pennylane-lightning/pull/974)

* Fix PTM stable-latest related to `default.qubit.legacy` and the `latest` flag usage. [(961)](https://github.com/PennyLaneAI/pennylane-lightning/pull/961) [(#966)](https://github.com/PennyLaneAI/pennylane-lightning/pull/966)

* Fix build failure for Lightning-Kokkos editable installation on MacOS due to `liblightning_kokkos_catalyst.so` copy and `liblightning_kokkos_catalyst.so` not copied to correct build path for editable installation. [(947)](https://github.com/PennyLaneAI/pennylane-lightning/pull/947) [(#968)](https://github.com/PennyLaneAI/pennylane-lightning/pull/968)

* Add concept restriction to ensure `ConstMult` inline function only hit with arithmetic-values times complex values. Fixes build failures with the test suite when enabling OpenMP, and disabling BLAS and Python under clang. [(936)](https://github.com/PennyLaneAI/pennylane-lightning/pull/936)

* Bug fix for `applyMatrix` in Lightning-Tensor. Matrix operator data is not stored in the `cuGateCache` object to support `TensorProd` obs with multiple `Hermitian` obs. [(932)](https://github.com/PennyLaneAI/pennylane-lightning/pull/932)

* Bug fix for `_pauli_word` of `QuantumScriptSerializer`. `_pauli_word` can process `PauliWord` object: `I`. [(919)](https://github.com/PennyLaneAI/pennylane-lightning/pull/919)

* Bug fix for analytic `qml.probs` in the Lightning-Tensor C++ API. [(906)](https://github.com/PennyLaneAI/pennylane-lightning/pull/906)

Contributors

This release contains contributions from (in alphabetical order):

Ali Asadi, Amintor Dusko, Diego Guala, Joseph Lee, Luis Alfredo Nuñez Meneses, Vincent Michaud-Rioux, Lee J. O'Riordan, Mudit Pandey, Shuli Shu, Haochen Paul Wang

New features since last release

* Add `qml.StatePrep()` and `qml.QubitStateVector()` support to `lightning.tensor`. [(849)](https://github.com/PennyLaneAI/pennylane-lightning/pull/849)

* Add analytic `qml.probs()` measurement support to `lightning.tensor`. [(830)](https://github.com/PennyLaneAI/pennylane-lightning/pull/830)

* Add `qml.state()` measurement support to `lightning.tensor`. [(827)](https://github.com/PennyLaneAI/pennylane-lightning/pull/827)

* Add Lightning-GPU Linux (AArch64 + GraceHopper) wheels to PyPI. [(815)](https://github.com/PennyLaneAI/pennylane-lightning/pull/815)

* Add `var` support to `lightning.tensor`. Note that `var` support is added via `obs**2` and this implementation scales as `O(num_obs**2)`. [(804)](https://github.com/PennyLaneAI/pennylane-lightning/pull/804)

Breaking changes

* Update python packaging to follow PEP 517/518/621/660 standards. [(832)](https://github.com/PennyLaneAI/pennylane-lightning/pull/832)

* Add `getData()` in the `lightning.tensor` C++ backend. Users are responsible for ensuring sufficient host memory is allocated for the full state vector. [(827)](https://github.com/PennyLaneAI/pennylane-lightning/pull/827)

* Remove `NDpermuter.hpp` which is no longer required. [(795)](https://github.com/PennyLaneAI/pennylane-lightning/pull/795)

* Remove temporary steps from the CI, such as downgrading Scipy to <1.14 and installing Kokkos v4.2 for `lightning-version == 'stable'`. [(792)](https://github.com/PennyLaneAI/pennylane-lightning/pull/792)

* Do not run GPU tests and Docker workflows on release. [(788)](https://github.com/PennyLaneAI/pennylane-lightning/pull/788)

Improvements

* Update Lightning tests to support the generalization of basis state preparation. [(864)](https://github.com/PennyLaneAI/pennylane-lightning/pull/864)

* Add `SetState` and `SetBasisState` to `LightningKokkosSimulator`. [(861)](https://github.com/PennyLaneAI/pennylane-lightning/pull/861)

* Remove use of the deprecated `Operator.expand` in favour of `Operator.decomposition`. [(846)](https://github.com/PennyLaneAI/pennylane-lightning/pull/846)

* The `setBasisState` and `setStateVector` methods of `StateVectorLQubit` and `StateVectorKokkos` are overloaded to support PennyLane-like parameters. [(843)](https://github.com/PennyLaneAI/pennylane-lightning/pull/843)

* Move `setBasisState`, `setStateVector` and `resetStateVector` from `StateVectorLQubitManaged` to `StateVectorLQubit`. [(841)](https://github.com/PennyLaneAI/pennylane-lightning/pull/841)

* Update `generate_samples` in `LightningKokkos` and `LightningGPU` to support `qml.measurements.Shots` type instances. [(839)](https://github.com/PennyLaneAI/pennylane-lightning/pull/839)

* Add a Catalyst-specific wrapping class for Lightning Kokkos. [(837)](https://github.com/PennyLaneAI/pennylane-lightning/pull/837) [(#770)](https://github.com/PennyLaneAI/pennylane-lightning/pull/770)

* Lightning-Qubit natively supports the `PauliRot` gate. [(834)](https://github.com/PennyLaneAI/pennylane-lightning/pull/834)

* Multiple calls to the `append_mps_final_state()` API is allowed in `lightning.tensor`. [(830)](https://github.com/PennyLaneAI/pennylane-lightning/pull/830)

* Add `initial_state_prep` option to Catalyst TOML file. [(826)](https://github.com/PennyLaneAI/pennylane-lightning/pull/826)

* `ENABLE_LAPACK` is `OFF` by default for all Lightning backends. [(825)](https://github.com/PennyLaneAI/pennylane-lightning/pull/825)

* Update `ctrl_decomp_zyz` tests with `len(control_wires) > 1`. [(821)](https://github.com/PennyLaneAI/pennylane-lightning/pull/821)

* Update the Catalyst-specific wrapping class for Lightning Kokkos to track Catalyst's new support for MCM seeding. [(819)](https://github.com/PennyLaneAI/pennylane-lightning/pull/819)

* Replace ``size_t`` by ``std::size_t`` everywhere. [(816)](https://github.com/PennyLaneAI/pennylane-lightning/pull/816/)

* Shot batching is made more efficient by executing all the shots in one go on Lightning-Qubit. [(814)](https://github.com/PennyLaneAI/pennylane-lightning/pull/814)

* Lightning-Qubit calls `generate_samples(wires)` on a minimal subset of wires when executing in finite-shot mode. [(813)](https://github.com/PennyLaneAI/pennylane-lightning/pull/813)

* Update `LightingQubit.preprocess` to work with changes to preprocessing for mid-circuit measurements. [(812)](https://github.com/PennyLaneAI/pennylane-lightning/pull/812)

* Avoid unnecessary memory reset in Lightning-Qubit's state vector class constructor. [(811)](https://github.com/PennyLaneAI/pennylane-lightning/pull/811)

* Add `generate_samples(wires)` support in Lightning-Qubit, which samples faster for a subset of wires. [(809)](https://github.com/PennyLaneAI/pennylane-lightning/pull/809)

* Optimize the OpenMP parallelization of Lightning-Qubit's `probs` for all number of targets. [(807)](https://github.com/PennyLaneAI/pennylane-lightning/pull/807)

* Optimize `probs(wires)` of Lightning-Kokkos using various kernels. Which kernel is to be used depends on the device, number of qubits and number of target wires. [(802)](https://github.com/PennyLaneAI/pennylane-lightning/pull/802)

* Add GPU device compute capability check for Lightning-Tensor. [(803)](https://github.com/PennyLaneAI/pennylane-lightning/pull/803)

* Refactor CUDA utils Python bindings to a separate module. [(801)](https://github.com/PennyLaneAI/pennylane-lightning/pull/801)

* Parallelize Lightning-Qubit `probs` with OpenMP when using the `-DLQ_ENABLE_KERNEL_OMP=1` CMake argument. [(800)](https://github.com/PennyLaneAI/pennylane-lightning/pull/800)

* Implement `probs(wires)` using a bit-shift implementation akin to the gate kernels in Lightning-Qubit. [(795)](https://github.com/PennyLaneAI/pennylane-lightning/pull/795)

* Enable setting the PennyLane version when invoking, for example, `make docker-build version=master pl_version=master`. [(791)](https://github.com/PennyLaneAI/pennylane-lightning/pull/791)

Documentation

* The installation instructions for all lightning plugins have been improved. [(858)](https://github.com/PennyLaneAI/pennylane-lightning/pull/858) [(#851)](https://github.com/PennyLaneAI/pennylane-lightning/pull/851)

* Updated the README and added citation format for Lightning arXiv preprint. [(818)](https://github.com/PennyLaneAI/pennylane-lightning/pull/818)

Bug fixes

* Point to the right Lightning root folder independently from the invocation location, when configuring the project. [(874)](https://github.com/PennyLaneAI/pennylane-lightning/pull/874)

* Update dependencies and `build` command options following changes in the build system. [(863)](https://github.com/PennyLaneAI/pennylane-lightning/pull/863)

* Replace structured bindings by variables in `GateImplementationsLM.hpp`. [(856)](https://github.com/PennyLaneAI/pennylane-lightning/pull/856)

* Remove wrong `-m` when calling `setup.py`. [(854)](https://github.com/PennyLaneAI/pennylane-lightning/pull/854)

* Fix plugin-test-matrix CI/CD workflows. [(850)](https://github.com/PennyLaneAI/pennylane-lightning/pull/850)

* Set the `immutable` parameter value as `false` for the `cutensornetStateApplyTensorOperator` to allow the following `cutensornetStateUpdateTensorOperator` call. [(845)](https://github.com/PennyLaneAI/pennylane-lightning/pull/845)

* Fix cuQuantum SDK path pass-thought in CMake. [(831)](https://github.com/PennyLaneAI/pennylane-lightning/pull/831)

* Fix CUDA sync issues on AArch64 + GraceHopper. [(823)](https://github.com/PennyLaneAI/pennylane-lightning/pull/823)

* Check for the number of wires for Hermitian observables in Lightning-Tensor. Only 1-wire Hermitian observables are supported as of `cuTensorNet-v24.03.0`. [(806)](https://github.com/PennyLaneAI/pennylane-lightning/pull/806)

* Set `PL_BACKEND` for the entire `build-wheel-lightning-gpu` Docker-build stage to properly build the Lightning-GPU wheel. [(791)](https://github.com/PennyLaneAI/pennylane-lightning/pull/791)

* Fix conditions for skipping build & push steps in the Docker build workflows. [(790)](https://github.com/PennyLaneAI/pennylane-lightning/pull/790)

* Downgrade Scipy on Lightning stable version tests. [(783)](https://github.com/PennyLaneAI/pennylane-lightning/pull/783)

* Fix checkout command in test workflows for rc branches. [(777)](https://github.com/PennyLaneAI/pennylane-lightning/pull/777)

Contributors

This release contains contributions from (in alphabetical order):

Ali Asadi, Astral Cai, Ahmed Darwish, Amintor Dusko, Vincent Michaud-Rioux, Erick Ochoa Lopez, Lee J. O'Riordan, Mudit Pandey, Shuli Shu, Raul Torres, Paul Haochen Wang

New features since last release

* Implement Python interface to the `lightning.tensor` device. [(748)](https://github.com/PennyLaneAI/pennylane-lightning/pull/748)

* Add `inverse` support for gate operations in `lightning.tensor` in the C++ layer. [(753)](https://github.com/PennyLaneAI/pennylane-lightning/pull/753)

* Add `observable` and `expval` support to the `cutensornet`-backed `lightning.tensor` C++ layer. [(728)](https://github.com/PennyLaneAI/pennylane-lightning/pull/728)

* Add gate support to `cutensornet`-backed `lightning.tensor` C++ layer. [(718)](https://github.com/PennyLaneAI/pennylane-lightning/pull/718)

* Add `cutensornet`-backed `MPS` C++ layer to `lightning.tensor`. [(704)](https://github.com/PennyLaneAI/pennylane-lightning/pull/704)

* Add support for `C(BlockEncode)` to Lightning devices. [(743)](https://github.com/PennyLaneAI/pennylane-lightning/pull/743)

Breaking changes

* Removed the `QuimbMPS` class and the corresponding backend from `lightning.tensor`. [(737)](https://github.com/PennyLaneAI/pennylane-lightning/pull/737)

* Changed the name of `default.tensor` to `lightning.tensor` with the `quimb` backend. [(730)](https://github.com/PennyLaneAI/pennylane-lightning/pull/730)

* `dynamic_one_shot` uses shot-vectors in the auxiliary tape to tell the device how many times to repeat the tape. Lightning-Qubit is updated accordingly. [(724)](https://github.com/PennyLaneAI/pennylane-lightning/pull/724)

* `dynamic_one_shot` deals with post-selection during the post-processing phase, so Lightning-Qubit does not return `None`-valued measurements for mismatching samples anymore. [(720)](https://github.com/PennyLaneAI/pennylane-lightning/pull/720)

Improvements

* Release candidate branches automatically use the new large GitHub runner pool. [(769)](https://github.com/PennyLaneAI/pennylane-lightning/pull/769)

* Lightning-Kokkos dev wheels for MacOS (x86_64, ARM64) and Linux (aarch64) are uploaded to TestPyPI upon merging a pull request. [(765)](https://github.com/PennyLaneAI/pennylane-lightning/pull/765)

* Lightning-Kokkos Linux (x86_64) dev wheels are pushed to [Test PyPI](https://test.pypi.org/project/PennyLane-Lightning-Kokkos/) upon merging a pull request. [(#763)](https://github.com/PennyLaneAI/pennylane-lightning/pull/763)

* Change the type of tensor network objects passed to `ObservablesTNCuda` and `MeasurementsTNCuda` classes from `StateTensorT` to `TensorNetT`. [(759)](https://github.com/PennyLaneAI/pennylane-lightning/pull/759)

* Silence `NDPermuter` linting warnings. [(750)](https://github.com/PennyLaneAI/pennylane-lightning/pull/750)

* Rationalize MCM tests, removing most end-to-end tests from the native MCM test file, but keeping one that validates multiple mid-circuit measurements with any allowed return. [(754)](https://github.com/PennyLaneAI/pennylane/pull/754)

* Rename `lightning.tensor` C++ libraries. [(755)](https://github.com/PennyLaneAI/pennylane-lightning/pull/755)

* Set `state_tensor` as `const` for the `MeasurementTNCuda` class. [(753)](https://github.com/PennyLaneAI/pennylane-lightning/pull/753)

* Updated Kokkos version and support to 4.3.01. [(725)](https://github.com/PennyLaneAI/pennylane-lightning/pull/725)

* Lightning-Kokkos' functors are rewritten as functions wrapping around generic gate and generator functors templated over a coefficient interaction function. This reduces boilerplate while clarifying how the various kernels differ from one another. [(640)](https://github.com/PennyLaneAI/pennylane-lightning/pull/640)

* Update C++ and Python GitHub actions names to include the matrix info. [(717)](https://github.com/PennyLaneAI/pennylane-lightning/pull/717)

* Remove `CPhase` in favour of `CPhaseShift` in Lightning devices. [(717)](https://github.com/PennyLaneAI/pennylane-lightning/pull/717)

* The various OpenMP configurations of Lightning-Qubit are tested in parallel on different Github Actions runners. [(712)](https://github.com/PennyLaneAI/pennylane-lightning/pull/712)

* Update Linux wheels to use `manylinux_2_28` images. [(667)](https://github.com/PennyLaneAI/pennylane-lightning/pull/667)

* Add support for `qml.expval` and `qml.var` in the `lightning.tensor` device for the `quimb` interface and the MPS method. [(686)](https://github.com/PennyLaneAI/pennylane-lightning/pull/686)

* Changed the name of `lightning.tensor` to `default.tensor` with the `quimb` backend. [(719)](https://github.com/PennyLaneAI/pennylane-lightning/pull/719)

* `lightning.qubit` and `lightning.kokkos` adhere to user-specified mid-circuit measurement configuration options. [(736)](https://github.com/PennyLaneAI/pennylane-lightning/pull/736)

* Patch the C++ `Measurements.probs(wires)` method in Lightning-Qubit and Lightning-Kokkos to `Measurements.probs()` when called with all wires.
This will trigger a more optimized implementation for calculating the probabilities of the entire system. [(744)](https://github.com/PennyLaneAI/pennylane-lightning/pull/744)

* Remove the daily schedule from the "Compat Check w/PL - release/release" GitHub action. [(746)](https://github.com/PennyLaneAI/pennylane-lightning/pull/746)

* Remove the required `scipy` config file for LightningQubit. The support is now maintained by passing `SCIPY_LIBS_PATH` to the compiler. [(775)](https://github.com/PennyLaneAI/pennylane-lightning/pull/775)

Documentation

* Add installation instructions and documentation for `lightning.tensor`. [(756)](https://github.com/PennyLaneAI/pennylane-lightning/pull/756)

Bug fixes

* Don't route `probs(wires=[])` to `probs(all_wires)` in Lightning-Kokkos. [(762)](https://github.com/PennyLaneAI/pennylane-lightning/pull/762)

* `ControlledQubitUnitary` is present in the Python device but not the TOML files. It is added to the decomposition gates since it can be implemented in its alternate form of `C(QubitUnitary)`. [(767)](https://github.com/PennyLaneAI/pennylane-lightning/pull/767)

* Update the Lightning TOML files to indicate that non-commuting observables are supported. [(764)](https://github.com/PennyLaneAI/pennylane-lightning/pull/764)

* Fix regex matching issue with auto on-boarding of release candidate branch to using the large runner queue. [(774)](https://github.com/PennyLaneAI/pennylane-lightning/pull/774)

* Fix random CI failures for `lightning.tensor` Python unit tests and ignore `lightning_tensor` paths. [(761)](https://github.com/PennyLaneAI/pennylane-lightning/pull/761)

* `lightning.qubit` and `lightning.kokkos` use `qml.ops.Conditional.base` instead of `qml.ops.Conditional.then_op`. [(752)](https://github.com/PennyLaneAI/pennylane-lightning/pull/752)

* The preprocessing step in `lightning.qubit` now uses interface information to properly support the hardware-like postselection for mid-circuit measurements. [(760)](https://github.com/PennyLaneAI/pennylane-lightning/pull/760)

* Fix AVX streaming operation support with newer GCC. [(729)](https://github.com/PennyLaneAI/pennylane-lightning/pull/729)

* Revert changes calling the templated `IMAG`, `ONE`, `ZERO` functions in Kokkos kernels since they are incompatible with device execution. [(733)](https://github.com/PennyLaneAI/pennylane-lightning/pull/733)

* The `tests_lkcpu_python.yml` workflow properly checks out the release or stable version of Lightning-Qubit during the test job. [(723)](https://github.com/PennyLaneAI/pennylane-lightning/pull/723)

* Fix PennyLane Lightning-Kokkos and LightningQubit tests for stable/stable configuration. [(734)](https://github.com/PennyLaneAI/pennylane-lightning/pull/734)

* Remove the Autoray dependency from requirement files. [(736)](https://github.com/PennyLaneAI/pennylane-lightning/pull/736)

* Fix the `cuda-runtime-12-0` dependency issue on RHEL8. [(739)](https://github.com/PennyLaneAI/pennylane-lightning/pull/739)

* Fix the memory segmentation fault when initializing zero-wire Lightning-Kokkos. [(757)](https://github.com/PennyLaneAI/pennylane-lightning/pull/757)

* Remove `pennylane.ops.op_math.controlled_decompositions.ctrl_decomp_zyz` tests with `len(control_wires) > 1`. [(757)](https://github.com/PennyLaneAI/pennylane-lightning/pull/757)

* Add support for Scipy v1.14. [(776)](https://github.com/PennyLaneAI/pennylane-lightning/pull/776)

* Add pickle support for the `DevPool` object in `lightning.gpu`. [(772)](https://github.com/PennyLaneAI/pennylane-lightning/pull/772)

Contributors

This release contains contributions from (in alphabetical order):

Ali Asadi, Amintor Dusko, Lillian Frederiksen, Pietropaolo Frisoni, David Ittah, Vincent Michaud-Rioux, Lee James O'Riordan, Mudit Pandey, Shuli Shu, Jay Soni

New features since last release

* Add compile-time support for AVX2/512 streaming operations in `lightning.qubit`. [(664)](https://github.com/PennyLaneAI/pennylane-lightning/pull/664)

* `lightning.kokkos` supports mid-circuit measurements. [(672)](https://github.com/PennyLaneAI/pennylane-lightning/pull/672)

* Add dynamic linking to LAPACK/OpenBlas shared objects in `scipy.libs` for both C++ and Python layer. [(653)](https://github.com/PennyLaneAI/pennylane-lightning/pull/653)

* `lightning.qubit` supports mid-circuit measurements. [(650)](https://github.com/PennyLaneAI/pennylane-lightning/pull/650)

* Add finite shots support in `lightning.qubit2`. [(630)](https://github.com/PennyLaneAI/pennylane-lightning/pull/630)

* Add `collapse` and `normalize` methods to the `StateVectorLQubit` classes, enabling "branching" of the wavefunction. Add methods to create and seed an RNG in the `Measurements` modules. [(645)](https://github.com/PennyLaneAI/pennylane-lightning/pull/645)

* Add two new python classes (LightningStateVector and LightningMeasurements) to support `lightning.qubit2`. [(613)](https://github.com/PennyLaneAI/pennylane-lightning/pull/613)

* Add analytic-mode `qml.probs` and `qml.var` support in `lightning.qubit2`. [(627)](https://github.com/PennyLaneAI/pennylane-lightning/pull/627)

* Add `LightningAdjointJacobian` to support `lightning.qubit2`. [(631)](https://github.com/PennyLaneAI/pennylane-lightning/pull/631)

* Add `lightning.qubit2` device which uses the new device API. [(607)](https://github.com/PennyLaneAI/pennylane-lightning/pull/607) [(#628)](https://github.com/PennyLaneAI/pennylane-lightning/pull/628)

* Add Vector-Jacobian Product calculation support to `lightning.qubit`. [(644)](https://github.com/PennyLaneAI/pennylane-lightning/pull/644)

* Add support for using new operator arithmetic as the default. [(649)](https://github.com/PennyLaneAI/pennylane-lightning/pull/649)

Breaking changes

* Split Lightning-Qubit and Lightning-Kokkos CPU Python tests with `pytest-split`. Remove `SERIAL` from Kokkos' `exec_model` matrix. Remove `all` from Lightning-Kokkos' `pl_backend` matrix. Move `clang-tidy` checks to `tidy.yml`. Avoid editable `pip` installations. [(696)](https://github.com/PennyLaneAI/pennylane-lightning/pull/696)

* Update `lightning.gpu` and `lightning.kokkos` to raise an error instead of falling back to `default.qubit`. [(689)](https://github.com/PennyLaneAI/pennylane-lightning/pull/689)

* Add `paths` directives to test workflows to avoid running tests that cannot be impacted by changes. [(699)](https://github.com/PennyLaneAI/pennylane-lightning/pull/699) [(#695)](https://github.com/PennyLaneAI/pennylane-lightning/pull/695)

* Move common components of `/src/simulator/lightning_gpu/utils/` to `/src/utils/cuda_utils/`. [(676)](https://github.com/PennyLaneAI/pennylane-lightning/pull/676)

* Deprecate static LAPACK linking support. [(653)](https://github.com/PennyLaneAI/pennylane-lightning/pull/653)

* Migrate `lightning.qubit` to the new device API. [(646)](https://github.com/PennyLaneAI/pennylane-lightning/pull/646)

* Introduce `ci:build_wheels` label, which controls wheel building on `pull_request` and other triggers. [(648)](https://github.com/PennyLaneAI/pennylane-lightning/pull/648)

* Remove building wheels for Lightning Kokkos on Windows. [(693)](https://github.com/PennyLaneAI/pennylane-lightning/pull/693)

Improvements

* Add tests for Windows Wheels, fix ill-defined caching, and set the proper backend for `lightning.kokkos` wheels. [(693)](https://github.com/PennyLaneAI/pennylane-lightning/pull/693)

* Replace string comparisons by `isinstance` checks where possible. [(691)](https://github.com/PennyLaneAI/pennylane-lightning/pull/691)

* Refactor `cuda_utils` to remove its dependency on `custatevec.h`. [(681)](https://github.com/PennyLaneAI/pennylane-lightning/pull/681)

* Add `test_templates.py` module where Grover and QSVT are tested. [(684)](https://github.com/PennyLaneAI/pennylane-lightning/pull/684)

* Create `cuda_utils` for common usage of CUDA related backends. [(676)](https://github.com/PennyLaneAI/pennylane-lightning/pull/676)

* Refactor `lightning_gpu_utils` unit tests to remove the dependency on statevector class. [(675)](https://github.com/PennyLaneAI/pennylane-lightning/pull/675)

* Upgrade GitHub actions versions from v3 to v4. [(669)](https://github.com/PennyLaneAI/pennylane-lightning/pull/669)

* Initialize the private attributes `gates_indices_` and `generators_indices_` of `StateVectorKokkos` using the definitions of the `Pennylane::Gates::Constant` namespace. [(641)](https://github.com/PennyLaneAI/pennylane-lightning/pull/641)

* Add `isort` to `requirements-dev.txt` and run before `black` upon `make format` to sort Python imports. [(623)](https://github.com/PennyLaneAI/pennylane-lightning/pull/623)

* Improve support for new operator arithmetic with `QuantumScriptSerializer.serialize_observables`. [(670)](https://github.com/PennyLaneAI/pennylane-lightning/pull/670)

* Add `workflow_dispatch` to wheels recipes; allowing developers to build wheels manually on a branch instead of temporarily changing the headers. [(679)](https://github.com/PennyLaneAI/pennylane-lightning/pull/679)

* Add the `ENABLE_LAPACK` compilation flag to toggle dynamic linking to LAPACK library. [(678)](https://github.com/PennyLaneAI/pennylane-lightning/pull/678)

Documentation

Bug fixes

* Fix wire order permutations when using `qml.probs` with out-of-order wires. [(707)](https://github.com/PennyLaneAI/pennylane-lightning/pull/707)

* Lightning Qubit once again respects the wire order specified on device instantiation. [(705)](https://github.com/PennyLaneAI/pennylane-lightning/pull/705)

* `dynamic_one_shot` was refactored to use `SampleMP` measurements as a way to return the mid-circuit measurement samples. `LightningQubit`'s `simulate` is modified accordingly. [(694)](https://github.com/PennyLaneAI/pennylane-lightning/pull/694)

* `LightningQubit` correctly decomposes state prep operations when used in the middle of a circuit. [(687)](https://github.com/PennyLaneAI/pennylane-lightning/pull/687)

* `LightningQubit` correctly decomposes `qml.QFT` and `qml.GroverOperator` if `len(wires)` is greater than 9 and 12 respectively. [(687)](https://github.com/PennyLaneAI/pennylane-lightning/pull/687)

* Specify `isort` `--py` (Python version) and `-l` (max line length) to stabilize `isort` across Python versions and environments. [(647)](https://github.com/PennyLaneAI/pennylane-lightning/pull/647)

* Fix random `coverage xml` CI issues. [(635)](https://github.com/PennyLaneAI/pennylane-lightning/pull/635)

* `lightning.qubit` correctly decomposed state preparation operations with adjoint differentiation. [(661)](https://github.com/PennyLaneAI/pennylane-lightning/pull/661)

* Fix the failed observable serialization unit tests. [(683)](https://github.com/PennyLaneAI/pennylane-lightning/pull/683)

* Update the `LightningQubit` new device API to work with Catalyst. [(665)](https://github.com/PennyLaneAI/pennylane-lightning/pull/665)

* Update the version of `codecov-action` to v4 and fix the CodeCov issue with the PL-Lightning check-compatibility actions. [(682)](https://github.com/PennyLaneAI/pennylane-lightning/pull/682)

* Refactor of dev prerelease auto-update-version workflow. [(685)](https://github.com/PennyLaneAI/pennylane-lightning/pull/685)

* Remove gates unsupported by catalyst from toml file. [(698)](https://github.com/PennyLaneAI/pennylane-lightning/pull/698)

* Increase tolerance for a flaky test. [(703)](https://github.com/PennyLaneAI/pennylane-lightning/pull/703)

Contributors

This release contains contributions from (in alphabetical order):

Ali Asadi, Amintor Dusko, Thomas Germain, Christina Lee, Erick Ochoa Lopez, Vincent Michaud-Rioux, Rashid N H M, Lee James O'Riordan, Mudit Pandey, Shuli Shu