# $\textit{Ab initio}$ prediction of a two-dimensional variant of the iridate IrO$_2$

## TL;DR

This paper predicts a novel two-dimensional insulating phase of IrO$_2$ with unique magnetic properties, using ab initio evolutionary algorithms, highlighting its potential for unusual magnetic phenomena unlike previously studied systems.

## Contribution

The study introduces a new 2D IrO$_2$ phase predicted by ab initio methods, revealing complex magnetic degeneracies and soft moments not seen in other iridates.

## Key findings

- Predicted a stable 2D IrO$_2$ phase with van der Waals crystal structure.
- Discovered highly degenerate magnetic states with easy plane anisotropy.
- Identified IrO$_2$ as a candidate for unusual magnetic behaviors.

## Abstract

We propose an insulating 2D phase of IrO$_{2}$, predicted by $\textit{ab initio}$ evolutionary algorithms. The predicted phase is a van der Waals crystal, in which Ir forms a triangular lattice, and is energetically competitive with the metastable spinel phase, observed experimentally. Electronic structure calculations show that the magnetic properties of this phase are highly nontrivial, with an almost perfect degeneracy of 120$^{\circ}$ $\textit{Neel}$ and $Y$-stripe orders, and unusually soft magnetic moments. The resulting behavior, which we term $\textit{easy plane anisotropy}$, is entirely different from what is realized in previously-explored Kitaev honeycomb lattices. Our results thus suggest that IrO$_{2}$ may be an ideal candidate to realize highly unusual magnetic properties.