Spontaneous Symmetry Breaking and Strong Deformations in Metal Adsorbed Graphene Sheets

TL;DR

This study investigates how lithium adsorption causes unexpected strong out-of-plane deformations and spontaneous symmetry breaking in graphene and similar sheets, revealing complex deformation behaviors beyond initial symmetric assumptions.

Contribution

It demonstrates the occurrence of spontaneous symmetry breaking in metal-adsorbed graphene sheets, highlighting deformation differences between single and double adsorption cases.

Findings

Double adsorption induces stronger deformations than single adsorption.

Spontaneous symmetry breaking occurs despite symmetric adsorption configurations.

Similar behaviors observed in Boron-Nitrogen sheets and other light alkalines.

Abstract

We study the adsorption of Li to graphene flakes described as aromatic molecules. Surprisingly the out of plane deformation is much stronger for the double adsorption from both sides to the same ring than for a single adsorption, although a symmetric solution seems possible. We thus have an interesting case of spontaneous symmetry breaking. While we cannot rule out a Jahn Teller deformation with certainty, this explanation seems unlikely and other options are discussed. We find a similar behavior for Boron-Nitrogen sheets, and also for other light alkalines.