Changelog
=========
Added
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- NFT optimizer, part of a project of Qiskit Camp Asia 2019 (729)
- Algorithm interface and result classes (849)
- Chemistry FCIDump file driver (859)
- Automatic Z2 symmetry reduction in the chemistry module (870)
- Ising optimization: The 0-1 Knapsack problem (878)
- VQE, VQC and QSVM accept `QuantumCircuit`s as variational forms/feature maps (905)
- New `GSLS` (Gaussian Smoothing Line Search) optimizer for variational algorithms (877)
- Qiskit's optimization module: a full toolset for solving quadratic programs (877)
- QuadraticProblem: A class representing quadratic programs with quadratic and linear objective and constraints
- OptimizationAlgorithm: A base class for optimization algorithm
- OptimizationResult: A base class for optimization results
- Summary of the optimization algorithms:
- MinimumEigenOptimizer: An optimization algorithm using a minimum eigen solver, such as VQE (or a classical
alternative). See the MinimumEigenSolver algorithms in Aqua.
- GroverOptimizer: The Grover Adaptive Search algorithm (Gilliam et al.)
- ADMMOptimizer: The ADMM-based heuristic (Gambella et al.)
- RecursiveMinimumEigenOptimizer: A meta-algorithm applying recursive optimization on top of a
MinimumEigenOptimizer (Bravyi et al.)
- CobylaOptimizer: Wrapping of SciPy’s COBYLA subroutine as optimization algorithm
- CplexOptimizer: Wrapping the CPLEX API as optimization algorithm
- A set of converters to translate different problem representations
- InequalityToEquality: Converts inequality constraints to equality constraints by adding slack variables
- IntegerToBinary: Converts integer variables to binary variables
- LinearEqualityToPenalty: Converts linear equality constraints to quadratic penalty terms that are added
to the objective
- QuadraticProgramToIsing: Converts a QuadraticProgram to an Aqua operator
- QuadraticProgramToNegativeValueOracle: Converts a QuadraticProgram to a negative-value oracle used for
Grover Adaptive Search
- QuadraticProgramToQubo: Converts a QuadraticProgram to a QUBO problem, a convenience converter wrapping the
functionality of the IntegerToBinary and LinearEqualityToPenalty converters
- IsingToQuadraticProgram: Converters an Aqua operator to a QuadraticProgram
- Operator flow, a set of tools for constructing Physically-intuitive quantum computations using State functions,
Operators, and Measurements, and relying on Terra's Operator objects as computational primitives (852)
- `OperatorBase`: A base class for Operators, State functions, Measurements, and combinations thereof
- `primitive_ops`: Classes for representing basic Operator building blocks, backed by computational
primitives in Terra. Includes `PrimitiveOp` (base and factory), `PauliOp`, `MatrixOp`, and `CircuitOp`
- `list_ops`: Classes for representing composite Operators, State functions, and Measurements constructed
from others, including `ListOp` (*non-abstract* parent), `SummedOp`, `ComposedOp`, and `TensoredOp`
- `state_fns`: Classes for representing State function and Measurement building blocks, backed by
primitives in Terra (other than `DictStateFn`, which is back by a `dict`). Includes
`StateFn` (base and factory), `DictStateFn`, `CircuitStateFn`, `VectorStateFn`, and `OperatorStateFn`
- `operator_globals`: A set of convenient immutable building block `OperatorBase` instances, including
single-qubit Paulis (`X`, `Y`, `Z`, `I`), basic gates (`H`, `CX`, `T`, `S`, `Swap`, `CZ`), and
single-qubit states (`Zero`, `One`, `Plus`, `Minus`)
- `converters`: Classes for manipulating and modifying Operators, including `ConverterBase` (base),
`CircuitSampler`, `PauliBasisChange`, `DictToCircuitSum`, and `AbelianGrouper`
- `expectations`: Converters for changing measurements of Observables to be more efficient or tractable,
including `ExpectationBase` (base), `ExpectationFactory` (factory), `PauliExpectation`,
`MatrixExpectation`, and `AerPauliExpectation`
- `evolutions`: Converters for changing Unitary evolutions of Hamiltonian Operators into
`CircuitOps` approximating or equalling the exponentiation e^(-iHt). Includes
`EvolutionBase` (base), `EvolutionFactory` (factory), `EvolvedOp` (lazy placeholder
Operator for evolution), `PauliTrotterEvolution`, `MatrixEvolution`,
`TrotterizationBase` (base), `TrotterizationFactory` (factory), `Trotter`,
`Suzuki`, and `QDrift`
- The QDrift Trotterization algorithm (852)
- Operator evolution using Terra's `HamiltonianGate` for improved performance (852)
Changed
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- Logical expression oracle improvements (821)
- Refactor Multiclass Extensions to set Estimator internally (822)
- Refactor algorithms (831) (849)
- Classical algorithms renamed, former names deprecated (851)
- Chemistry process algorithm result returns result object, lines, dict return deprecated (861)
- Measurement error mitigation supports different output orders on same qubits (865)
- If ibmq-provider is used and job limit is reached, `run_circuit` now waits for a previous job
to finish before submitting the next one. (906)
- Deprecate using `FeatureMap` and `VariationalForm` in VQC and QSVM (905)
- The Eigensolvers and MinimumEigensolvers now accept `OperatorBase` (Operator flow) Observables
in addition to the existing Operators (852).
- The `BaseOperator` was renamed `LegacyBaseOperator` to avoid confusion with the new
Operator flow `OperatorBase` (852).
- HartreeFock initial state and UCCSD variational form `num_qubits` parameter removed as it was
only value checked against that computed internally from the other parameters. UCCSD `depth`
parameter renamed to `reps` and moved in order so it can default to 1. (939)
Removed
-------
- Declarative api (758) (759) (760) (762) (763)
- Moved to Terra:
- multi-controlled Toffoli, U1 and Pauli rotation gates (including tests) (833)
- arithmetic circuits in qiskit/aqua/circuits (895)
- boolean logic gates (896)
- quantum Fourier transformation (909)
- the RY, RYRZ and SwapRZ variational forms (920)
- the PauliExpansion, First- and SecondOrderExpansion feature maps (920)
Fixed
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- Boolean logic circuit construction (819)
- Measurement on actual devices for Amplitude Estimation algorithms (841) (842)
- Supported constant values on the left-hand side of constraints and variables on the right-hand
side of constraints for the DOcplex translator (750)
- WeightedPauliOperator constructor simplification bug (891)
- TPBGroupedWeightedPauliOperator multiplication (915)