  We formulate an analytical recursive method to generate the wave function of
doped short-range resonating valence bond (RVB) states as a tool to efficiently
estimate multisite entanglement as well as other physical quantities in doped
quantum spin ladders. We prove that doped RVB ladder states are always genuine
multipartite entangled. Importantly, our results show that within specific
doping concentration and model parameter regimes, the doped RVB state
essentially characterizes the trends of genuine multiparty entanglement in the
exact ground states of the Hubbard model with large onsite interactions, in the
limit which yields the $t$-$J$ Hamiltonian.
