QFIBase

class qiskit.opflow.gradients.QFIBase(qfi_method='lin_comb_full')

Bases: DerivativeBase

Deprecated: Base class for Quantum Fisher Information (QFI).

Compute the Quantum Fisher Information (QFI) given a pure, parameterized quantum state.

The QFI is:

[QFI]kl= Re[〈∂kψ|∂lψ〉−〈∂kψ|ψ〉〈ψ|∂lψ〉] * 4.

0.24.0 ভার্সন থেকে ডেপ্রিকেটেড: The class qiskit.opflow.gradients.qfi_base.QFIBase is deprecated as of qiskit-terra 0.24.0. It will be removed no earlier than 3 months after the release date. For code migration guidelines, visit https://qisk.it/opflow_migration.

প্যারামিটার:

qfi_method (str | CircuitQFI) -- The method used to compute the state/probability gradient. Can be either a CircuitQFI instance or one of the following pre-defined strings 'lin_comb_full', 'overlap_diag'` or 'overlap_block_diag'`.

রেইজেস:

ValueError -- if qfi_method is neither a CircuitQFI object nor one of the predefined strings.

Attributes

qfi_method

Returns CircuitQFI.

রিটার্নস:

CircuitQFI.