Topological bands in the PdSe$_2$ pentagonal monolayer

TL;DR

This paper investigates the topological properties of monolayer PdSe2, revealing nontrivial conduction bands protected by symmetries and discussing their physical implications like spin Hall conductivity.

Contribution

It provides a comprehensive topological analysis of PdSe2 monolayer using first-principles calculations, symmetry indicators, and effective models, highlighting its nontrivial electronic structure.

Findings

Conduction bands are topologically nontrivial and symmetry-protected.

Numerical evidence confirms the nontrivial topological character.

Spin Hall conductivity is derived from the topological properties.

Abstract

The electronic structure of monolayer pentagonal palladium diselenide (PdSe2) is analyzed from the topological band theory perspective. Employing first-principles calculations, effective models and symmetry indicators, we find that the low-lying conduction bands are topologically nontrivial, protected by time reversal and crystalline symmetries. Numerical evidence supporting the nontrivial character of the bands is presented. Furthermore, we obtain a relevant physical response from the topological viewpoint, such as the spin Hall conductivity.