Orbital-selective confinement effect of Ru 4d orbitals in SrRuO3 ultrathin film

Abstract

The electronic structure of SrRuO3 thin film with thickness from 50 to 1 unit cell (u.c.) is investigated via the resonant inelastic x-ray scattering (RIXS) technique at the O K-edge to unravel the intriguing interplay of orbital and charge degrees of freedom. We found that orbital-selective quantum confinement effect (QCE) induces the splitting of Ru 4d orbitals. At the same time, we observed a clear suppression of the electron-hole continuum across the metal-to-insulator transition (MIT) occurring at the 4 u.c. sample. From these two clear observations we conclude that QCE gives rise to a Mott insulating phase in ultrathin SrRuO3 films. Our interpretation of the RIXS spectra is supported by the configuration interaction calculations of RuO6 clusters.PACS numbers: fill in later arXiv:1812.09844v1 [cond-mat.str-el]

Acidic Oxygen Evolution Reaction Activity–Stability Relationships in Ru-Based Pyrochlores

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Magnetic and electrical anisotropy with correlation and orbital effects in dimerized honeycomb ruthenate Li2RuO3

“…On a microscopic level, they are governed by a number of transition metal d electrons, the strength of spin-orbit coupling, the strength of correlation effects, the Hund's rule coupling, and the ionic radii of the A-site element [5,6]. As the relevant energy scales of these factors become more comparable to one another for 4d orbitals, the ground state of 4d transition metal oxides, in particular of ruthenates, becomes more sensitive to perturbation with the particular importance of the orbital degree of freedom [3,4,7]. One should also note that Ru has a moderate spin-orbit interaction of 75 meV as compared with its 5d counterparts.…”

Electric field controllable high-spin SrRuO3 driven by a solid ionic junction

“…Transition metal oxides (TMOs) with strong delectron correlations and spin-orbit coupling (SOC) may provide an effective platform towards emergent magnetism with controllable spin textures [12][13][14][15][16][17][18][19][20]. SrRuO3 (SRO) is a unique 4d TMO with a coexistence of SOC and itinerant ferromagnetism [21], leading to a large variety of physical behaviors which have been experimentally observed such as high-spin states driven by crystal orientations [22][23][24], magnetic skyrmions due to the broken symmetry [25][26][27][28], and metal-insulator transition [29][30][31], etc. More importantly, emergent physical behaviors have been theoretically proposed in SRO recently [13,15,32,33], triggering a broad attention to discover the potential quantum states in this material.…”