5
$\begingroup$

Other than the two famous parameter-shift rule and finite difference method, is there any other (perhaps simple) methods to estimate gradients of a cost function in variational quantum algorithms?

$\endgroup$

1 Answer 1

2
$\begingroup$

One scheme that's been used quite successfully in practice is SPSA. If you're using a simulator and keeping track of the entire state vector, another really efficient method is adjoint differentiation.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.