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.

References in corpus (6)

• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Magnetic order in $\alpha$-RuCl${}_3$: a honeycomb lattice quantum magnet with strong spin-orbit coupling
• Orbital-dependent singlet dimers and orbital-selective Peierls transitions in transition metal compounds
• Lattice-Tuned Magnetism of Ru4+(4d4) Ions in Single-Crystals of the Layered Honeycomb Ruthenates: Li2RuO3 and Na2RuO3
• Analysis of the optical conductivity for A2IrO3 (A = Na, Li) from first principles
• Electronic structure and the origin of the high ordering temperature in SrRu2O6

Cited by in corpus (4)

• Models and Materials for Generalized Kitaev Magnetism
• Electronic excitations in $\gamma$-Li${}_2$IrO${}_3$
• Magnetic and electronic ordering phenomena in the [Ru${}_2$O${}_6$] honeycomb lattice compound AgRuO${}_3$
• MoP${}_3$SiO${}_{11}$: a $4d^3$ honeycomb antiferromagnet with disconnected octahedra