LinCombEstimatorGradient¶

class LinCombEstimatorGradient(estimator, derivative_type=DerivativeType.REAL, options=None)[source]¶

Bases: 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

প্যারামিটার

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.

Methods

`run`	Run the job of the estimator gradient on the given circuits.
`update_default_options`	Update the gradient's default options 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).

রিটার্নস: 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.

রিটার্নস: The gradient default + estimator options.