LinCombEstimatorGradient#

class qiskit.algorithms.gradients.LinCombEstimatorGradient(estimator, derivative_type=DerivativeType.REAL, options=None)[ソース]#

ベースクラス: BaseEstimatorGradient

Compute the gradients of the expectation values. This method employs a linear combination of unitaries [1].

Reference: [1] Schuld et al., Evaluating analytic gradients on quantum hardware, 2018 arXiv:1811.11184

パラメータ:

  • estimator (BaseEstimator) – The estimator used to compute the gradients.

  • derivative_type (DerivativeType) –

    The type of derivative. Can be either DerivativeType.REAL DerivativeType.IMAG, or DerivativeType.COMPLEX. Defaults to DerivativeType.REAL.

    • DerivativeType.REAL computes \(2 \mathrm{Re}[⟨ψ(ω)|O(θ)|dω ψ(ω)〉]\).

    • DerivativeType.IMAG computes \(2 \mathrm{Im}[⟨ψ(ω)|O(θ)|dω ψ(ω)〉]\).

    • DerivativeType.COMPLEX computes \(2 ⟨ψ(ω)|O(θ)|dω ψ(ω)〉\).

  • options (Options | None) – Primitive backend runtime options used for circuit execution. The order of priority is: options in run method > gradient’s default options > primitive’s default setting. Higher priority setting overrides lower priority setting.

Attributes

SUPPORTED_GATES = ['rx', 'ry', 'rz', 'rzx', 'rzz', 'ryy', 'rxx', 'cx', 'cy', 'cz', 'ccx', 'swap', 'iswap', 'h', 't', 's', 'sdg', 'x', 'y', 'z']#
derivative_type#

Return the derivative type (real, imaginary or complex).

戻り値:

The derivative type.

options#

Return the union of estimator options setting and gradient default options, where, if the same field is set in both, the gradient’s default options override the primitive’s default setting.

戻り値:

The gradient default + estimator options.

Methods

run(circuits, observables, parameter_values, parameters=None, **options)#

Run the job of the estimator gradient on the given circuits.

パラメータ:

  • circuits (Sequence[QuantumCircuit]) – The list of quantum circuits to compute the gradients.

  • observables (Sequence[BaseOperator | PauliSumOp]) – The list of observables.

  • parameter_values (Sequence[Sequence[float]]) – The list of parameter values to be bound to the circuit.

  • parameters (Sequence[Sequence[Parameter] | None] | None) – The sequence of parameters to calculate only the gradients of the specified parameters. Each sequence of parameters corresponds to a circuit in circuits. Defaults to None, which means that the gradients of all parameters in each circuit are calculated. None in the sequence means that the gradients of all parameters in the corresponding circuit are calculated.

  • options – Primitive backend runtime options used for circuit execution. The order of priority is: options in run method > gradient’s default options > primitive’s default setting. Higher priority setting overrides lower priority setting

戻り値:

The job object of the gradients of the expectation values. The i-th result corresponds to circuits[i] evaluated with parameters bound as parameter_values[i]. The j-th element of the i-th result corresponds to the gradient of the i-th circuit with respect to the j-th parameter.

例外:

ValueError – Invalid arguments are given.

戻り値の型:

AlgorithmJob

update_default_options(**options)#

Update the gradient’s default options setting.

パラメータ:

**options – The fields to update the default options.