Speaker
Description
In the pursuit towards targeted material design leveraging strong electronic correlation, computationally inexpensive yet qualitatively reliable methods play a fundamental role. These approaches should allow for a rapid mapping of phase space, unveiling a first impression of possible phases of matter, which can then be explored in selected regions of parameter space with more accurate yet involved techniques. Recently, the ghost Gutzwiller Approximation (gGA) has been shown to be an interesting candidate for this kind of phenomenological search. Based on a self-consistency condition for the simple one-body reduced density matrix of a discretized impurity model, this method can capture spectral features of both coherent and incoherent nature in the one-body Green's function. In this work we assess its reliability in the multi-orbital regime, investigating systems presenting orbital-selective Mott transitions, Mott-to-band insulator transitions, and interaction-resilient Hund metallicity. Our results paint a promising picture for the potential of gGA for modelling of complex materials, possibly in combination with ab-initio methods.
