Almost pure $J_{\mathrm{eff}} = 1/2$ Mott state of In$_2$Ir$_2$O$_7$ in the limit of reduced inter-site hopping

TL;DR

This study reveals that In$_2$Ir$_2$O$_7$ exhibits an almost pure $J_{ ext{eff}}=1/2$ Mott state due to reduced inter-site hopping, highlighting the importance of hopping effects in spin-orbital Mott insulators.

Contribution

It demonstrates that reduced inter-site hopping leads to a nearly pure $J_{ ext{eff}}=1/2$ state in In$_2$Ir$_2$O$_7$, emphasizing the role of hopping in local physics of such materials.

Findings

In$_2$Ir$_2$O$_7$ has a small admixture of $J_{ ext{eff}}=3/2$ component.

Reduced inter-site hopping distinguishes In$_2$Ir$_2$O$_7$ from other pyrochlore iridates.

The effect of inter-site hopping is crucial in understanding the local physics of $J_{ ext{eff}}=1/2$ Mott insulators.

Abstract

The pyrochlore iridate In$_2$Ir$_2$O$_7$ is a strong $J_{\mathrm{eff}} = 1/2$ Mott insulator with frustrated magnetism. Despite the large trigonal crystal field, a small admixture of $J_{\mathrm{eff}} = 3/2$ component in the $J_{\mathrm{eff}} = 1/2$ bands and a small splitting of $J_{\mathrm{eff}} = 3/2$ bands are observed as compared with other pyrochlore iridates A$_2$Ir$_2$O$_7$ (A: trivalent cation). We argue that the reduced inter-site hopping between the $J_{\mathrm{eff}} = 1/2$ and the $J_{\mathrm{eff}} = 3/2$ manifold plays a predominant role in the distinct behavior of In$_2$Ir$_2$O$_7$ compared with other A$_2$Ir$_2$O$_7$. The effect of the intersite hopping should not be dismissed in the local physics of spin-orbital-entangled $J_{\mathrm{eff}} = 1/2$ Mott insulators.