Out-of-plane excitons in two-dimensional crystals

Guilhon , Marques M, Teles LK, Palummo M, Pulci O, Botti S, Bechstedt F (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Physical Review B American Physical Society

Book Volume: 99

Article Number: 161201

Journal Issue: 16

DOI: 10.1103/PhysRevB.99.161201

Abstract

Two-dimensional materials are ideal platforms to explore new physical phenomena and reveal unique optical properties. Excitonic and quasiparticle effects are strongly enhanced by the reduced screening. The response to a perturbing electromagnetic field is dominated by in-plane light polarization. The quantum confinement of the atomic sheets in normal direction also allows out-of-plane pair excitations, which are ruled by selection rules and local-field effects. We apply the GW approximation and the Bethe-Salpeter equation to investigate optical transitions for light polarization both parallel and normal to the atomic planes. Prototypical systems range from semimetals to large-gap insulators such as graphene, graphene oxide, boron nitride, and molybdenum disulfide. For the considered materials, the out-of-plane absorption edge and the first van Hove singularities are blueshifted in dependence of the effective sheet thickness, while the intensity of the optical conductivity is reduced by orders of magnitude.

Involved external institutions

Instituto Tecnológico de Aeronáutica BR Brazil (BR) Università degli Studi di Roma 'Tor Vergata' IT Italy (IT) Friedrich-Schiller-Universität Jena DE Germany (DE)

How to cite

APA:

Guilhon, ., Marques, M., Teles, L.K., Palummo, M., Pulci, O., Botti, S., & Bechstedt, F. (2019). Out-of-plane excitons in two-dimensional crystals. Physical Review B, 99(16). https://doi.org/10.1103/PhysRevB.99.161201

MLA:

Guilhon, , et al. "Out-of-plane excitons in two-dimensional crystals." Physical Review B 99.16 (2019).

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