I was wondering if there is a possibility to report measurement components when reporting the final expectation values of a qubit operator. For example, if we look at a simple Hydrogen molecule Hamiltonian (parity mapping, minimal basis, $0.7414$ Å) as follows:

$$H_{op} = -1.052\, II + 0.397\, IZ -0.397\, ZI -0.011 \, ZZ + 0.180 \,XX$$

To obtain the ground state energy, we need to calculate the expectation value of the above expression. To my understanding, this can be done using PauliExpectation() function from aqua. For this problem, I assume expectation values are computed for each component ($II$, $IZ$, $ZI$, $ZZ$, $XX$) of the above Hamiltonian (multiplied by the pre-factors: $-1.05, 0.39, 0.39, -0.01, 0.18$) and then summed up.

I am wondering if it's possible to report the expectation values for each component, ie just for the $IZ$, $ZI$, $ZZ$ and $XX$ terms, for example. I could very easily then multiply the pre-factors and compute the total expectation value classically.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.