Evolution of a band insulating phase from a correlated metallic phase

Abstract

We investigate the evolution of the electronic structure in SrRu_(1-x)Ti_xO_3 as a function of x using high resolution photoemission spectroscopy, where SrRuO3 is a weakly correlated metal and SrTiO3 is a band insulator. The surface spectra exhibit a metal-insulator transition at x = 0.5 by opening up a soft gap. A hard gap appears at higher x values consistent with the transport properties. In contrast, the bulk spectra reveal a pseudogap at the Fermi level, and unusual evolution exhibiting an apparent broadening of the coherent feature and subsequent decrease in intensity of the lower Hubbard band with the increase in x. Interestingly, the first principle approaches are found to be sufficient to capture anomalous evolutions at high energy scale. Analysis of the spectral lineshape indicates strong interplay between disorder and electron correlation in the electronic properties of this system.

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References in corpus (4)

• Quantum Monte Carlo Study of an Interaction-Driven Band Insulator to Metal Transition
• Role of covalency in the ground state properties of perovskite ruthenates: A first principle study using local spin density approximations
• Observation of particle hole asymmetry and phonon excitations in non-Fermi liquid systems: A high-resolution photoemission study of ruthenates
• Manifestation of lattice distortions in the O 1s spectra in Ca1-xSrxRuO3

Cited by in corpus (2)

• Single-particle excitations under coexisting electron correlation and disorder: a numerical study of the Anderson-Hubbard model
• Soft Hubbard gaps in disordered itinerant models with short-range interaction