Release 0.38.0

New features since last release

Registers of wires 🧸

• A new function called qml.registers has been added that lets you seamlessly create registers of wires. (#5957) (#6102)

  Using registers, it is easier to build large algorithms and circuits by applying gates and operations to predefined collections of wires. With qml.registers, you can create registers of wires by providing a dictionary whose keys are register names and whose values are the number of wires in each register.

  >>> wire_reg = qml.registers({"alice": 4, "bob": 3})
  >>> wire_reg
  {'alice': Wires([0, 1, 2, 3]), 'bob': Wires([4, 5, 6])}

  The resulting data structure of qml.registers is a dictionary with the same register names as keys, but the values are qml.wires.Wires instances.

  Nesting registers within other registers can be done by providing a nested dictionary, where the ordering of wire labels is based on the order of appearance and nestedness.

  >>> wire_reg = qml.registers({"alice": {"alice1": 1, "alice2": 2}, "bob": {"bob1": 2, "bob2": 1}})
  >>> wire_reg
  {'alice1': Wires([0]), 'alice2': Wires([1, 2]), 'alice': Wires([0, 1, 2]), 'bob1': Wires([3, 4]), 'bob2': Wires([5]), 'bob': Wires([3, 4, 5])}

  Since the values of the dictionary are Wires instances, their use within quantum circuits is very similar to that of a list of integers.

  dev = qml.device("default.qubit")
  
  @qml.qnode(dev)
  def circuit():
      for w in wire_reg["alice"]:
          qml.Hadamard(w)
  
      for w in wire_reg["bob1"]:
          qml.RX(0.1967, wires=w)
  
      qml.CNOT(wires=[wire_reg["alice1"][0], wire_reg["bob2"][0]])
  
      return [qml.expval(qml.Y(w)) for w in wire_reg["bob1"]]
  
  print(qml.draw(circuit)())

  0: ──H────────╭●─┤     
  1: ──H────────│──┤     
  2: ──H────────│──┤     
  3: ──RX(0.20)─│──┤  <Y>
  4: ──RX(0.20)─│──┤  <Y>
  5: ───────────╰X─┤  

  In tandem with qml.registers, we've also made the following improvements to qml.wires.Wires:

  • Wires instances now have a more copy-paste friendly representation when printed. (#5958)

    >>> from pennylane.wires import Wires
    >>> w = Wires([1, 2, 3])
    >>> w
    Wires([1, 2, 3])

  • Python set-based combinations are now supported by Wires. (#5983)

    This new feature unlocks the ability to combine Wires instances in the following ways:

    • intersection with & or intersection():

      >>> wires1 = Wires([1, 2, 3])
      >>> wires2 = Wires([2, 3, 4])
      >>> wires1.intersection(wires2) # or wires1 & wires2
      Wires([2, 3])

    • symmetric difference with ^ or symmetric_difference():

      >>> wires1.symmetric_difference(wires2) # or wires1 ^ wires2
      Wires([1, 4])

    • union with | or union():

      >>> wires1.union(wires2) # or wires1 | wires2
      Wires([1, 2, 3, 4])

    • difference with - or difference():

      >>> wires1.difference(wires2) # or wires1 - wires2
      Wires([1])

Quantum arithmetic operations 🧮

• Several new operator templates have been added to PennyLane that let you perform quantum arithmetic operations. (#6109) (#6112) (#6121)

  • qml.Adder performs in-place modular addition: $\text{Adder}(k, m)\vert x \rangle = \vert x + k ; \text{mod} ; m\rangle$.

  • qml.PhaseAdder is similar to qml.Adder, but it performs in-place modular addition in the Fourier basis.

  • qml.Multiplier performs in-place multiplication: $\text{Multiplier}(k, m)\vert x \rangle = \vert x \times k ; \text{mod} ; m \rangle$.

  • qml.OutAdder performs out-place modular addition: $\text{OutAdder}(m)\vert x \rangle \vert y \rangle \vert b \rangle = \vert x \rangle \vert y \rangle \vert b + x + y ; \text{mod} ; m \rangle$.

  • qml.OutMultiplier performs out-place modular multiplication: $\text{OutMultiplier}(m)\vert x \rangle \vert y \rangle \vert b \rangle = \vert x \rangle \vert y \rangle \vert b + x \times y ; \text{mod} ; m \rangle$.

  • qml.ModExp performs modular exponentiation: $\text{ModExp}(base, m) \vert x \rangle \vert k \rangle = \vert x \rangle \vert k \times base^x ; \text{mod} ; m \rangle$.

  Here is a comprehensive example that performs the following calculation: (2 + 1) * 3 mod 7 = 2 (or 010 in binary).

  dev = qml.device("default.qubit", shots=1)
  
  wire_reg = qml.registers({
      "x_wires": 2, # |x>: stores the result of 2 + 1 = 3
      "y_wires": 2, # |y>: multiples x by 3
      "output_wires": 3, # stores the result of (2 + 1) * 3 m 7 = 2
      "work_wires": 2 # for qml.OutMultiplier
  })
  
  @qml.qnode(dev)
  def circuit():
      # In-place addition
      qml.BasisEmbedding(2, wires=wire_reg["x_wires"])
      qml.Adder(1, x_wires=wire_reg["x_wires"]) # add 1 to wires [0, 1] 
  
      # Out-place multiplication
      qml.BasisEmbedding(3, wires=wire_reg["y_wires"])
      qml.OutMultiplier(
          wire_reg["x_wires"], 
          wire_reg["y_wires"], 
          wire_reg["output_wires"], 
          work_wires=wire_reg["work_wires"], 
          mod=7
      ) 
  
      return qml.sample(wires=wire_reg["output_wires"])

  >>> circuit()
  array([0, 1, 0])
  

Converting noise models from Qiskit ♻️

• Convert Qiskit noise models into a PennyLane NoiseModel with qml.from_qiskit_noise. (#5996)

  In the last few releases, we've added substantial improvements and new features to the Pennylane-Qiskit plugin. With this release, a new qml.from_qiskit_noise function allows you to convert a Qiskit noise model into a PennyLane NoiseModel. Here is a simple example with two quantum errors that add two different depolarizing errors based on the presence of different gates in the circuit:

  import pennylane as qml
  import qiskit_aer.noise as noise
  
  error_1 = noise.depolarizing_error(0.001, 1) # 1-qubit noise
  error_2 = noise.depolarizing_error(0.01, 2) # 2-qubit noise
  
  noise_model = noise.NoiseModel()
  
  noise_model.add_all_qubit_quantum_error(error_1, ['rz', 'ry'])
  noise_model.add_all_qubit_quantum_error(error_2, ['cx'])

  >>> qml.from_qiskit_noise(noise_model)
  NoiseModel({
    OpIn(['RZ', 'RY']): QubitChannel(num_kraus=4, num_wires=1)
    OpIn(['CNOT']): QubitChannel(num_kraus=16, num_wires=2)
  })

  Under the hood, PennyLane converts each quantum error in the Qiskit noise model into an equivalent qml.QubitChannel operator with the same canonical Kraus representation. Currently, noise models in PennyLane do not support readout errors. As such, those will be skipped during conversion if they are present in the Qiskit noise model.

  Make sure to pip install pennylane-qiskit to access this new feature!

Substantial upgrades to mid-circuit measurements using tree-traversal 🌳

• The "tree-traversal" algorithm for mid-circuit measurements (MCMs) on default.qubit has been internally redesigned for better performance. (#5868)

  In the last release (v0.37), we introduced the tree-traversal MCM method, which was implemented in a recursive way for simplicity. However, this had the unintended consequence of very deep stack calls for circuits with many MCMs, resulting in stack overflows in some cases. With this release, we've refactored the implementation of the tree-traversal method into an iterative approach, which solves those inefficiencies when many MCMs are present in a circuit.

• The tree-traversal algorithm is now compatible with analytic-mode execution (shots=None). (#5868)

  dev = qml.device("default.qubit")
  
  n_qubits = 5
  
  @qml.qnode(dev, mcm_method="tree-traversal")
  def circuit():
      for w in range(n_qubits):
          qml.Hadamard(w)
      
      for w in range(n_qubits - 1):
          qml.CNOT(wires=[w, w+1])
  
      for w in range(n_qubits):
          m = qml.measure(w)
          qml.cond(m == 1, qml.RX)(0.1967 * (w + 1), w)
  
      return [qml.expval(qml.Z(w)) for w in range(n_qubits)]

  >>> circuit()
  [tensor(0.00964158, requires_grad=True),
   tensor(0.03819446, requires_grad=True),
   tensor(0.08455748, requires_grad=True),
   tensor(0.14694258, requires_grad=True),
   tensor(0.2229438, requires_grad=True)]

Improvements 🛠

Creating spin Hamiltonians

• Three new functions are now available for creating commonly-used spin Hamiltonians in PennyLane: (#6106) (#6128)

  • qml.spin.transverse_ising creates the transverse-field Ising model Hamiltonian.
  • qml.spin.heisenberg creates the Heisenberg model Hamiltonian.
  • qml.spin.fermi_hubbard creates the Fermi-Hubbard model Hamiltonian.

  Each Hamiltonian can be instantiated by specifying a lattice, the number of unit cells, n_cells, and the Hamiltonian parameters as keyword arguments. Here is an example with the transverse-field Ising model:

  >>> tfim_ham = qml.spin.transverse_ising(lattice="square", n_cells=[2, 2], coupling=0.5, h=0.2)
  >>> tfim_ham
  (
      -0.5 * (Z(0) @ Z(1))
    + -0.5 * (Z(0) @ Z(2))
    + -0.5 * (Z(1) @ Z(3))
    + -0.5 * (Z(2) @ Z(3))
    + -0.2 * X(0)
    + -0.2 * X(1)
    + -0.2 * X(2)
    + -0.2 * X(3)
  )

  The resulting object is a qml.Hamiltonian instance, making it easy to use in circuits like the following.

  dev = qml.device("default.qubit", shots=1)
  
  @qml.qnode(dev)
  def circuit():
      return qml.expval(tfim_ham)

  >>> circuit()
  -2.0
  

  More features will be added to the qml.spin module in the coming releases, so stay tuned!

A Prep-Select-Prep template

• A new template called qml.PrepSelPrep has been added that implements a block-encoding of a linear combination of unitaries. (#5756) (#5987)

  This operator acts as a nice wrapper for having to perform qml.StatePrep, qml.Select, and qml.adjoint(qml.StatePrep) in succession, which is quite common in many quantum algorithms (e.g., LCU and block encoding). Here is an example showing the equivalence between using qml.PrepSelPrep and qml.StatePrep, qml.Select, and qml.adjoint(qml.StatePrep).

  coeffs = [0.3, 0.1]
  alphas = (np.sqrt(coeffs) / np.linalg.norm(np.sqrt(coeffs)))
  unitaries = [qml.X(2), qml.Z(2)]
  
  lcu = qml.dot(coeffs, unitaries)
  control = [0, 1]
  
  def prep_sel_prep(alphas, unitaries):
      qml.StatePrep(alphas, wires=control, pad_with=0)
      qml.Select(unitaries, control=control)
      qml.adjoint(qml.StatePrep)(alphas, wires=control, pad_with=0)
  
  @qml.qnode(qml.device("default.qubit"))
  def circuit(lcu, control, alphas, unitaries):
      qml.PrepSelPrep(lcu, control)
      qml.adjoint(prep_sel_prep)(alphas, unitaries)
      return qml.state()

  >>> import numpy as np
  >>> np.round(circuit(lcu, control, alphas, unitaries), decimals=2)
  tensor([1.+0.j -0.+0.j -0.+0.j -0.+0.j  0.+0.j  0.+0.j  0.+0.j  0.+0.j], requires_grad=True)

QChem improvements

• Molecules and Hamiltonians can now be constructed for all the elements present in the periodic table. (#5821)

  This new feature is made possible by integrating with the basis-set-exchange package. If loading basis sets from basis-set-exchange is needed for your molecule, make sure that you pip install basis-set-exchange and set load_data=True.

  symbols  = ['Ti', 'Ti']
  geometry = np.array([[0.0, 0.0, -1.1967],
                      [0.0, 0.0,  1.1967]], requires_grad=True)
  mol = qml.qchem.Molecule(symbols, geometry, load_data=True)

  >>> mol.n_electrons
  44

• qml.UCCSD now accepts an additional optional argument, n_repeats, which defines the number of times the UCCSD template is repeated. This can improve the accuracy of the template by reducing the Trotter error, but would result in deeper circuits. (#5801)

• The qml.qchem.qubit_observable function has been modified to return an ascending wire order for molecular Hamiltonians. (#5950)

• A new method called to_mat has been added to the qml.FermiWord and qml.FermiSentence classes, which allows for computing the matrix representation of these Fermi operators. (#5920)

Improvements to operators

• qml.GlobalPhase now supports parameter broadcasting. (#5923)

• qml.Hermitian now has a compute_decomposition method. (#6062)

• The implementation of qml.PhaseShift, qml.S, and qml.T has been improved, resulting in faster circuit execution times. (#5876)

• The qml.CNOT operator no longer decomposes into itself. Instead, it raises a qml.DecompositionUndefinedError. (#6039)

Mid-circuit measurements

• The qml.dynamic_one_shot transform now supports circuits using the "tensorflow" interface. (#5973)

• If the conditional does not include a mid-circuit measurement, then qml.cond will automatically evaluate conditionals using standard Python control flow. (#6016)

  This allows qml.cond to be used to represent a wider range of conditionals:

  dev = qml.device("default.qubit", wires=1)
  
  @qml.qnode(dev)
  def circuit(x):
      c = qml.cond(x > 2.7, qml.RX, qml.RZ)
      c(x, wires=0)
      return qml.probs(wires=0)

  >>> print(qml.draw(circuit)(3.8))
  0: ──RX(3.80)─┤  Probs
  >>> print(qml.draw(circuit)(0.54))
  0: ──RZ(0.54)─┤  Probs

Transforms

• qml.transforms.single_qubit_fusion and qml.transforms.merge_rotations now respect global phases. (#6031)

• A new transform called qml.transforms.diagonalize_measurements has been added. This transform converts measurements to the computational basis by applying the relevant diagonalizing gates. It can be set to diagonalize only a subset of the base observables {qml.X, qml.Y, qml.Z, qml.Hadamard}. (#5829)

• A new transform called split_to_single_terms has been added. This transform splits expectation values of sums into multiple single-term measurements on a single tape, providing better support for simulators that can handle non-commuting observables but don't natively support multi-term observables. (#5884)

• New functionality has been added to natively support exponential extrapolation when using qml.transforms.mitigate_with_zne. This allows users to have more control over the error mitigation protocol without needing to add further dependencies. (#5972)

Capturing and representing hybrid programs

• qml.for_loop now supports range-like syntax with default step=1. (#6068)

• Applying adjoint and ctrl to a quantum function can now be captured into plxpr. Furthermore, the qml.cond function can be captured into plxpr. (#5966) (#5967) (#5999) (#6058)

• During experimental program capture, functions that accept and/or return pytree structures can now be handled in the qml.QNode call, qml.cond, qml.for_loop and qml.while_loop. (#6081)

• During experimental program capture, QNodes can now use closure variables. (#6052)

• Mid-circuit measurements can now be captured with qml.capture enabled. (#6015)

• qml.for_loop can now be captured into plxpr. (#6041) (#6064)

• qml.for_loop and qml.while_loop now fall back to standard Python control flow if @qjit is not present, allowing the same code to work with and without @qjit without any rewrites. (#6014)

  dev = qml.device("lightning.qubit", wires=3)
  
  @qml.qnode(dev)
  def circuit(x, n):
  
      @qml.for_loop(0, n, 1)
      def init_state(i):
          qml.Hadamard(wires=i)
  
      init_state()
  
      @qml.for_loop(0, n, 1)
      def apply_operations(i, x):
          qml.RX(x, wires=i)
  
          @qml.for_loop(i + 1, n, 1)
          def inner(j):
              qml.CRY(x**2, [i, j])
  
          inner()
          return jnp.sin(x)
  
      apply_operations(x)
      return qml.probs()

  >>> print(qml.draw(circuit)(0.5, 3))
  0: ──H──RX(0.50)─╭●────────╭●──────────────────────────────────────┤  Probs
  1: ──H───────────╰RY(0.25)─│──────────RX(0.48)─╭●──────────────────┤  Probs
  2: ──H─────────────────────╰RY(0.25)───────────╰RY(0.23)──RX(0.46)─┤  Probs
  >>> circuit(0.5, 3)
  array([0.125     , 0.125     , 0.09949758, 0.15050242, 0.07594666,
       0.11917543, 0.08942104, 0.21545687])
  >>> qml.qjit(circuit)(0.5, 3)
  Array([0.125     , 0.125     , 0.09949758, 0.15050242, 0.07594666,
       0.11917543, 0.08942104, 0.21545687], dtype=float64)

Community contributions 🥳

• Fixed a bug in qml.ThermalRelaxationError where there was a typo from tq to tg. (#5988)

• Readout error has been added using parameters readout_relaxation_probs and readout_misclassification_probs on the default.qutrit.mixed device. These parameters add a qml.QutritAmplitudeDamping and a qml.TritFlip channel, respectively, after measurement diagonalization. The amplitude damping error represents the potential for relaxation to occur during longer measurements. The trit flip error represents misclassification during readout. (#5842)

• qml.ops.qubit.BasisStateProjector now has a compute_sparse_matrix method that computes the sparse CSR matrix representation of the projector onto the given basis state. (#5790)

Other improvements

• qml.pauli.group_observables now uses rustworkx colouring algorithms to solve the Minimum Clique Cover problem, resulting in orders of magnitude performance improvements. (#6043)

  This adds two new options for the method argument: dsatur (degree of saturation) and gis (independent set). In addition, the creation of the adjacency matrix now takes advantage of the symplectic representation of the Pauli observables.

  Additionally, a new function called qml.pauli.compute_partition_indices has been added to calculate the indices from the partitioned observables more efficiently. These changes improve the wall time of qml.LinearCombination.compute_grouping and the grouping_type='qwc' by orders of magnitude.

• qml.counts measurements with all_outcomes=True can now be used with JAX jitting. Additionally, measurements broadcasted across all available wires (e.g., qml.probs()) can now be used with JAX jit and devices that allow dynamic numbers of wires (only 'default.qubit' currently). (#6108)

• qml.ops.op_math.ctrl_decomp_zyz can now decompose special unitaries with multiple control wires. (#6042)

• A new method called process_density_matrix has been added to the ProbabilityMP and DensityMatrixMP measurement processes, allowing for more efficient handling of quantum density matrices, particularly with batch processing support. This method simplifies the calculation of probabilities from quantum states represented as density matrices. (#5830)

• SProd.terms now flattens out the terms if the base is a multi-term observable. (#5885)

• qml.QNGOptimizer now supports cost functions with multiple arguments, updating each argument independently. (#5926)

• semantic_version has been removed from the list of required packages in PennyLane. (#5836)

• qml.devices.LegacyDeviceFacade has been added to map the legacy devices to the new device interface, making it easier for developers to develop legacy devices. (#5927)

• StateMP.process_state now defines rules in cast_to_complex for complex casting, avoiding a superfluous statevector copy in PennyLane-Lightning simulations. (#5995)

• QuantumScript.hash is now cached, leading to performance improvements. (#5919)

• Observable validation for default.qubit is now based on execution mode (analytic vs. finite shots) and measurement type (sample measurement vs. state measurement). This improves our error handling when, for example, non-hermitian operators are given to qml.expval. (#5890)

• A new is_leaf parameter has been added to the function flatten in the qml.pytrees module. This is to allow for node flattening to be stopped for any node where the is_leaf optional argument evaluates to being True. (#6107)

• A progress bar has been added to qml.data.load() when downloading a dataset. (#5560)

• Upgraded and simplified StatePrep and AmplitudeEmbedding templates. (#6034) (#6170)

• Upgraded and simplified BasisState and BasisEmbedding templates. (#6021)

Breaking changes 💔

• MeasurementProcess.shape(shots: Shots, device:Device) is now MeasurementProcess.shape(shots: Optional[int], num_device_wires:int = 0). This has been done to allow for jitting when a measurement is broadcasted across all available wires, but the device does not specify wires. (#6108)

• If the shape of a probability measurement is affected by a Device.cutoff property, it will no longer work with jitting. (#6108)

• qml.GlobalPhase is considered non-differentiable with tape transforms. As a consequence, qml.gradients.finite_diff and qml.gradients.spsa_grad no longer support differentiating qml.GlobalPhase with state-based outputs. (#5620)

• The CircuitGraph.graph rustworkx graph now stores indices into the circuit as the node labels, instead of the operator/ measurement itself. This allows the same operator to occur multiple times in the circuit. (#5907)

• The queue_idx attribute has been removed from the Operator, CompositeOp, and SymbolicOp classes. (#6005)

• qml.from_qasm no longer removes measurements from the QASM code. Use measurements=[] to remove measurements from the original circuit. (#5982)

• qml.transforms.map_batch_transform has been removed, since transforms can be applied directly to a batch of tapes. See qml.transform for more information. (#5981)

• QuantumScript.interface has been removed. (#5980)

Deprecations 👋

• The decomp_depth argument in qml.device has been deprecated. (#6026)

• The max_expansion argument in qml.QNode has been deprecated. (#6026)

• The expansion_strategy attribute qml.QNode has been deprecated. (#5989)

• The expansion_strategy argument has been deprecated in all of qml.draw, qml.draw_mpl, and qml.specs. The level argument should be used instead. (#5989)

• Operator.expand has been deprecated. Users should simply use qml.tape.QuantumScript(op.decomposition()) for equivalent behaviour. (#5994)

• qml.transforms.sum_expand and qml.transforms.hamiltonian_expand have been deprecated. Users should instead use qml.transforms.split_non_commuting for equivalent behaviour. (#6003)

• The expand_fn argument in qml.execute has been deprecated. Instead, please create a qml.transforms.core.TransformProgram with the desired preprocessing and pass it to the transform_program argument of qml.execute. (#5984)

• The max_expansion argument in qml.execute has been deprecated. Instead, please use qml.devices.preprocess.decompose with the desired expansion level, add it to a qml.transforms.core.TransformProgram and pass it to the transform_program argument of qml.execute. (#5984)

• The override_shots argument in qml.execute has been deprecated. Instead, please add the shots to the QuantumTapes to be executed. (#5984)

• The device_batch_transform argument in qml.execute has been deprecated. Instead, please create a qml.transforms.core.TransformProgram with the desired preprocessing and pass it to the transform_program argument of qml.execute. (#5984)

• qml.qinfo.classical_fisher and qml.qinfo.quantum_fisher have been deprecated. Instead, use qml.gradients.classical_fisher and qml.gradients.quantum_fisher. (#5985)

• The legacy devices default.qubit.{autograd,torch,tf,jax,legacy} have been deprecated. Instead, use default.qubit, as it now supports backpropagation through the several backends. (#5997)

• The logic for internally switching a device for a different backpropagation compatible device is now deprecated, as it was in place for the deprecated default.qubit.legacy. (#6032)

Documentation 📝

• The docstring for qml.qinfo.quantum_fisher, regarding the internally used functions and potentially required auxiliary wires, has been improved. (#6074)

• The docstring for QuantumScript.expand and qml.tape.tape.expand_tape has been improved. (#5974)

Bug fixes 🐛

• The sparse matrix can now be computed for a product operator when one operand is a GlobalPhase on no wires. (#6197)

• For default.qubit, JAX is now used for sampling whenever the state is a JAX array. This fixes normalization issues that can occur when the state uses 32-bit precision. (#6190)

• Fix Pytree serialization of operators with empty shot vectors (#6155)

• Fixes an error in the dynamic_one_shot transform when used with sampling a single shot. (#6149)

• qml.transforms.pattern_matching_optimization now preserves the tape measurements. (#6153)

• qml.transforms.broadcast_expand no longer squeezes out batch sizes of size 1, as a batch size of 1 is still a batch size. (#6147)

• Catalyst replaced argnum with argnums in gradient related functions, therefore we updated the Catalyst calls to those functions in PennyLane. (#6117)

• fuse_rot_angles now returns NaN instead of incorrect derivatives at singular points. (#6031)

• qml.GlobalPhase and qml.Identity can now be captured with plxpr when acting on no wires. (#6060)

• Fixed jax.grad and jax.jit to work for qml.AmplitudeEmbedding, qml.StatePrep and qml.MottonenStatePreparation. (#5620)

• Fixed a bug in qml.center that omitted elements from the center if they were linear combinations of input elements. (#6049)

• Fix a bug where the global phase returned by one_qubit_decomposition gained a broadcasting dimension. (#5923)

• Fixed a bug in qml.SPSAOptimizer that ignored keyword arguments in the objective function. (#6027)

• Fixed dynamic_one_shot for use with devices using the old device API, since override_shots was deprecated. (#6024)

• CircuitGraph can now handle circuits with the same operation instance occuring multiple times. (#5907)

• qml.QSVT has been updated to store wire order correctly. (#5959)

• qml.devices.qubit.measure_with_samples now returns the correct result if the provided measurements contain a sum of operators acting on the same wire. (#5978)

• qml.AmplitudeEmbedding has better support for features using low precision integer data types. (#5969)

• qml.BasisState and qml.BasisEmbedding now works with jax.jit, lightning.qubit, and give the correct decomposition. (#6021)

• Jacobian shape has been fixed for measurements with dimension in qml.gradients.vjp.compute_vjp_single. (5986)

• qml.lie_closure now works with sums of Paulis. (#6023)

• Workflows that parameterize the coefficients of qml.exp are now jit-compatible. (#6082)

• Fixed a bug where CompositeOp.overlapping_ops changes the original ordering of operators, causing an incorrect matrix to be generated for Prod with Sum as operands. (#6091)

• qml.qsvt now works with "Wx" convention and any number of angles. (#6105)

• Basis set data from the Basis Set Exchange library can now be loaded for elements with SPD-type orbitals. (#6159)

Contributors ✍️

This release contains contributions from (in alphabetical order):

Tarun Kumar Allamsetty, Guillermo Alonso, Ali Asadi, Utkarsh Azad, Tonmoy T. Bhattacharya, Gabriel Bottrill, Jack Brown, Ahmed Darwish, Astral Cai, Yushao Chen, Ahmed Darwish, Diksha Dhawan Maja Franz, Lillian M. A. Frederiksen, Pietropaolo Frisoni, Emiliano Godinez, Austin Huang, Renke Huang, Josh Izaac, Soran Jahangiri, Korbinian Kottmann, Christina Lee, Jorge Martinez de Lejarza, William Maxwell, Vincent Michaud-Rioux, Anurav Modak, Mudit Pandey, Andrija Paurevic, Erik Schultheis, nate stemen, David Wierichs,