| Our level of understanding of correlated electron systems has seen substantial advancements in the last years due to improved variational wavefunctions of generalized Gutzwiller-RVB type. In particular, we present a new kind of holon-doublon correlation, the so-called backflow correlations. They allow to treat correctly the large-U limit of the Hubbard model and are crucial to stabilize a spin-liquid insulating phase, in presence of frustration. Here, we focus on the role of backflow correlations in improving our undertanding of the underlying Fermi surface in the insulating phase. Indeed, we show a novel renormalization of the underlying Fermi surface to perfect nesting, close to the Mott-Hubbard transition. |
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