Design and Predict Tetragonal van der Waals Layered Quantum Materials of MPd$_5$I$_2$ (M=Ga, In and 3$d$ Transition Metals)

TL;DR

This study uses high-throughput density functional theory to design and predict new tetragonal van der Waals layered quantum materials with topological and magnetic properties, expanding the known MPd$_5$I$_2$ family.

Contribution

It introduces a systematic approach to discovering new vdW quantum materials with tunable topological and magnetic features in the MPd$_5$I$_2$ structure.

Findings

TiPd$_5$I$_2$ and InPd$_5$I$_2$ host Dirac points and potential topological insulator states.

CrPd$_5$I$_2$ exhibits ferromagnetism with high out-of-plane magneto-anisotropy.

Multiple new materials with topological and magnetic properties are predicted in the MPd$_5$I$_2$ family.

Abstract

Quantum materials with stacked van der Waals (vdW) layers hosting non-trivial band structure topology and magnetism have shown many interesting properties. Using high throughput density functional theory calculations, we design and predict tetragonal vdW-layered quantum materials in the MPd$_5$I$_2$ structure (M=Ga, In and 3d transition metals). We show that besides the known AlPd$_5$I$_2$, the -MPd$_5$- structural motif of three-atomic-layer slabs separated by two I layers can accommodate a variety of metal atoms giving arise to topologically non-trivial features and highly tunable magnetic properties in both bulk and single layer 2D structures. Among them, TiPd$_5$I$_2$ and InPd$_5$I$_2$ host a pair of Dirac points and likely an additional strong topological insulator state for the band manifolds just above and below the top valence band, respectively, with their single layers hosting or near quantum spin Hall states. CrPd$_5$I$_2$ is a ferromagnet with a large out-of-plane magneto-anisotropy energy, desirable for rare-earth-free permanent magnets.