Is there a way to directly measure sums of site operators and squares of sums of site operators? (I am using the directed loop SSE code, but I think this question also applied to other algorithms.) I could accomplish this indirectly by measuring the local site operators and also measuring correlations between the site operators and then adding them together (to manually expand the square), but if there is a way to do this directly, that would seem to be a more elegant/pretty solution. The motivation for this questions is that I need to compute the “Magnetization" and “Magnetization Squared” — which already exists as pre-created measurements — but my system has site dependent g values, so instead of measuring the sum of Sz_i (the square of the sum), I need to measure the sum of g_i***Sz_i (and the square of the sum), where the sum extends over all sites, i.
Is this possible? If so, can you provide an example?
Thanks!
Larry