ImaginaryMcLachlanPrinciple¶
 class ImaginaryMcLachlanPrinciple(qgt=None, gradient=None)[source]¶

Class for an Imaginary McLachlan’s Variational Principle. It aims to minimize the distance between both sides of the Wickrotated Schrödinger equation with a quantum state given as a parametrized trial state. The principle leads to a system of linear equations handled by a linear solver. The imaginary variant means that we consider imaginary time dynamics.
 Parameters
qgt (BaseQGT  None) – Instance of a the GQT class used to compute the QFI. If
None
provided,LinCombQGT
is used.gradient (BaseEstimatorGradient  None) – Instance of a class used to compute the state gradient. If
None
provided,LinCombEstimatorGradient
is used.
 Raises
AlgorithmError – If the gradient instance does not contain an estimator.
Methods Defined Here
Calculates an evolution gradient according to the rules of this variational principle.