Spectroscopic signatures of molecular orbitals on a honeycomb lattice

Abstract

A tendency to form benzene-like molecular orbitals has been recently shown to be a common feature of the $4d$ and $5d$ transition metal oxides with a honeycomb lattice. This tendency competes with other interactions such as the spin-orbit coupling and Hubbard correlations, and can be partially or completely suppressed. In the calculations, SrRu${}_2$O${}_6$ presents the cleanest, so far, case of well-formed molecular orbitals, however, direct experimental evidence for or against this proposition has been missing. In this paper, we show that combined photoemission and optical studies can be used to identify molecular orbitals in SrRu${}_2$O${}_6$. Symmetry-driven election selection rules suppress optical transitions between certain molecular orbitals, while photoemission and inverse photoemission measurements are insensitive to them. Comparing the photoemission and optical conductivity spectra one should be able to observe clear signatures of molecular orbitals.

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Cited by in corpus (8)

• Models and Materials for Generalized Kitaev Magnetism
• Orbital effects in solids: basics, recent progress and opportunities
• Orbital physics in transition metal compounds: new trends
• Magnetic and electronic ordering phenomena in the [Ru${}_2$O${}_6$] honeycomb lattice compound AgRuO${}_3$
• Electronic excitations in $\gamma$-Li${}_2$IrO${}_3$
• Raman spectroscopy of the low dimensional antiferromagnet with large Neel temperature SrRu2O6
• MoP${}_3$SiO${}_{11}$: a $4d^3$ honeycomb antiferromagnet with disconnected octahedra
• Non-van der Waals honeycomb antiferromagnet SrRu${}_2$O${}_6$ down to a few layers