  Due to the presence of strong correlations, theoretical or experimental
investigations of quantum many-body systems belong to the most challenging
tasks in modern physics. Stimulated by tensor networks, we propose a scheme of
constructing the few-body models that can be easily accessed by theoretical or
experimental means, to accurately capture the ground-state properties of
infinite many-body systems in higher dimensions. The general idea is to embed a
small bulk of the infinite model in an "entanglement bath" so that the
many-body effects can be faithfully mimicked. The approach we propose is
efficient, simple, flexible, sign-problem-free, and it directly accesses the
thermodynamic limit. The numerical results of the spin models on honeycomb and
simple cubic lattices show that the ground-state properties including quantum
phase transitions and the critical behaviors are accurately captured by only
$\mathcal{O}(10)$ physical and bath sites. Moreover, since the few-body
Hamiltonian only contains local interactions among a handful of sites, our work
provides new ways of studying the many-body phenomena in the infinite
strongly-correlated systems by mimicking them in the few-body experiments using
cold atoms/ions, or developing novel quantum devices by utilizing the many-body
features.
