First Principles Study of the Optical Dipole Trap for Two-Dimensional Excitons in Graphane

TL;DR

This paper proposes a first-principles method to create optical dipole traps for excitons in graphane, enabling precise control of light-matter interactions in two-dimensional semiconductors.

Contribution

It introduces a novel ab initio approach combining density functional theory and GW+BSE to evaluate exciton properties for trapping applications in 2D materials.

Findings

Large exciton binding energy in graphane facilitates deep traps.

Significant dipole moments enable meV-depth and micron-scale traps.

The method provides a robust framework for exciton manipulation in 2D systems.

Abstract

Recent studies on excitons in two-dimensional materials have been widely conducted for their potential usages for novel electronic and optical devices. Especially, sophisticated manipulation techniques of quantum degrees of freedom of excitons are demanded. In this paper we propose a technique of forming an optical dipole trap for excitons in graphane, a two-dimensional wide gap semiconductor, based on first principles calculations. We develop a first principles method to evaluate the exciton transition dipole matrix and combine it with the density functional theory and GW+BSE calculations. We reveal that in graphane the huge exciton binding energy and the large dipole moments of Wannier-like excitons enable us to induce the dipole trap of the order of meV depth and $\mu$m width. This work opens a new way to control light-exciton interacting systems based on a newly developed numerically robust ab initio calculations.