Naslov
Nonadiabatic renormalization of electron-phonon interaction in graphene based materials

Autori
Girotto, Nina ; Novko, Dino

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
DPG-Frühjahrstagung (DPG Spring Meeting) of the Surface Science Division

Mjesto i datum
Virtualni skup, 01.03.2021. - 04.03.2021

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
phonon, electron-phonon interaction, DFT, nonadiabaticity

Sažetak
Some of the most prominent features of two- dimensional (2D) materi- als issue from electron-phonon coupling (EPC) and are easily tailored by strain and doping. Phonon-mediated superconductivity is expected in a variety of 2D materials, and because the transition temperature within the Bardeen-Cooper-Schrieffer (BCS) theory increases with in- creasing EPC, tailoring EPC provides a recipe for a more feasible real- ization of superconductors. Here, we present density-functional-theory (DFT) calculations of EPC properties of doped 2D systems, specifi- cally highly-doped graphene and hole-doped graphane. Doping equal- izes the energy scales of electron transitions and phonon frequencies, but using the adiabatic Born-Oppenheimer approximation, DFT as- sumes nuclear and electronic motion can be separated. We show that the mentioned approximation is not applicable on studied systems, since the adiabatically obtained phonon spectrum is at significant vari- ance with the one containing nonadiabatic corrections. Nonadiabatic renormalization greatly modifies the EPC strength, which in turn al- ters the superconducting transition temperature prediction, rendering its calculation more reliable. The importance of including dynamical corrections is indisputable and care should be taken when neglecting nonadiabatic effects as they have a huge impact not only on the mag- nitude of the EPC strength and the transition temperature, but also on the qualitative understanding of the system in question.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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