Analysis of the optical conductivity for A2IrO3 (A = Na, Li) from first principles

TL;DR

This paper investigates the optical conductivity of Na2IrO3 and Li2IrO3 using first-principles calculations, revealing how quasi-molecular orbitals influence optical transitions and comparing the two compounds.

Contribution

It provides a detailed first-principles analysis of optical conductivity in Na2IrO3 and Li2IrO3, highlighting the role of quasi-molecular orbitals and their parity in optical transitions.

Findings

Identification of interband transition features in Na2IrO3

Quasi-molecular orbital parity governs optical transition strength

Comparison of optical properties between Na2IrO3 and Li2IrO3

Abstract

We present results for the optical conductivity of Na2IrO3 within density functional theory by including spin-orbit (SO) and correlation effects (U) as implemented in GGA+SO+U. We identify the various interband transitions and show that the underlying quasi-molecular-orbital nature of the electronic structure in Na2IrO3 translates into distinct features in the optical conductivity. Most importantly, the parity of the quasi-molecular orbitals appears to be the main factor in determining strong and weak optical transitions. We also present optical conductivity calculations for Li2IrO3 and discuss the similarities and differences with Na2IrO3.