Eur. Phys. J. B (2012) 85: 320
https://doi.org/10.1140/epjb/e2012-30105-4

Regular Article

Zero point motion effect on the electronic properties of diamond, trans-polyacetylene and polyethylene

¹ Nano-Bio Spectroscopy Group and ETSF Scientific Development Center, Dpto. Física de Materiales, Centro de Física de Materiales CSIC-UPV/EHU-MPC and DIPC, Universidad del País Vasco UPV/EHU, Avenida Tolosa 72, 20018 San Sebastián, Spain
² Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche, Via Salaria Km 29.5, CP 10, 00016 Monterotondo Stazione, Italy

^a e-mail: elena.cannuccia@gmail.com

Received: 31 January 2012
Received in final form: 11 July 2012
Published online: 24 September 2012

Abstract

It has been recently shown, using ab-initio  methods, that bulk diamond is characterized by a large band-gap renormalization (~0.6 eV) induced by the electron-phonon interaction. In this work we show that in polymers, compared to bulk materials, the larger amplitude of the atomic vibrations makes the real excitations of the system be composed by entangled electron-phonon states. We prove that these states carry only a fraction of the electronic charge, thus leading, inevitably, to the failure of the electronic picture. The present results cast doubts on the accuracy of purely electronic calculations. They also lead to a critical revision of the state-of-the-art description of carbon-based nanostructures, opening a wealth of potential implications.