Eur. Phys. J. B (2014) 87: 26
https://doi.org/10.1140/epjb/e2013-40492-5

Regular Article

Exciton swapping in a twisted graphene bilayer as a solid-state realization of a two-brane model

¹ Research Center in Physics of Matter and Radiation, University of Namur, 61 rue de Bruxelles, 5000 Namur, Belgium
² BCRC (Member of EMRA), 4 avenue du gouverneur Cornez, 7000 Mons, Belgium

^a e-mail: michael.sarrazin@unamur.be

Received: 15 May 2013
Received in final form: 24 September 2013
Published online: 27 January 2014

Abstract

It is shown that exciton swapping between two graphene sheets may occur under specific conditions. A magnetically tunable optical filter is described to demonstrate this new effect. Mathematically, it is shown that two turbostratic graphene layers can be described as a “noncommutative” two-sheeted (2 + 1)-spacetime thanks to a formalism previously introduced for the study of braneworlds in high energy physics. The Hamiltonian of the model contains a coupling term connecting the two layers which is similar to the coupling existing between two braneworlds at a quantum level. In the present case, this term is related to a K-K^′ intervalley coupling. In addition, the experimental observation of this effect could be a way to assess the relevance of some theoretical concepts of the braneworld hypothesis.