



01066nas a2200145   4500008004100000245006700041210006700108260001400175520061300189100002100802700001900823700002200842700001900864856003700883       2022                        eng d00aNISQ algorithm for the matrix elements of a generic observable0 aNISQ algorithm for the matrix elements of a generic observable  c5/20/20223 a<p>The calculation of off-diagonal matrix elements has various applications in fields such as nuclear physics and quantum chemistry. In this paper, we present a noisy intermediate scale quantum algorithm for estimating the diagonal and off-diagonal matrix elements of a generic observable in the energy eigenbasis of a given Hamiltonian. Several numerical simulations indicate that this approach can find many of the matrix elements even when the trial functions are randomly initialized across a wide range of parameter values without, at the same time, the need to prepare the energy eigenstates.&nbsp;</p>1 aErbanni, Rebecca1 aBharti, Kishor1 aKwek, Leong-Chuan1 aPoletti, Dario  uhttps://arxiv.org/abs/2205.10058