Plasmon Spectrum of Single Layer Antimonene

TL;DR

This paper calculates the plasmon spectrum of 2D antimonene beyond simple models, revealing complex inter-band modes influenced by spin-orbit interaction, using a detailed tight-binding and RPA approach.

Contribution

It provides a comprehensive calculation of the plasmon spectrum of antimonene including spin-orbit effects, extending beyond low-energy approximations.

Findings

Rich spectrum with intra-band and inter-band modes

Spin-orbit interaction causes new inter-band branches

Interaction between inter-band modes and plasmons

Abstract

The collective excitation spectrum of two-dimensional (2D) antimonene is calculated beyond the low energy continuum approximation. The dynamical polarizability is computed using a 6-orbitals tight-binding model that properly accounts for the band structure of antimonene in a broad energy range. Electron-electron interaction is considered within the random phase approximation. The obtained spectrum is rich, containing the standard intra-band 2D plasmon and a set of single inter-band modes. We find that spin-orbit interaction plays a fundamental role in the reconstruction of the excitation spectrum, with the emergence of novel inter-band branches in the continuum that interact with the plasmon.