Pressure-induced orbital-selective metal from the Mott insulator <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>BaFe</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Se</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math>
L. Craco, Stefano Leoni
Abstract
A general understanding of the mechanism underlying the pressure-induced Mott insulator-metal transition in strongly correlated materials is still lacking. Here we explore the pressure-induced electronic reconstruction in ${\mathrm{BaFe}}_{2}{\mathrm{Se}}_{3}$, a potential two-leg ladder system for unconventional (non-BCS) superconductivity. We stress the importance of multiorbital Coulomb interactions in concert with first-principles band-structure calculations for a consistent understanding of its intrinsic Mott-Hubbard insulating state both at ambient and under pressure. We elucidate the nature of pressure-induced insulator-metal transition seen in experiment, showing that it is driven by bandwidth broadening under pressure. We reveal an orbital-selective electronic state where Mott localized and itinerant electrons coexist in compressed ${\mathrm{BaFe}}_{2}{\mathrm{Se}}_{3}$, which incorporates orbital-resolved scattering rates and renormalization factors hidden in the normal state at high pressures.