Open AccessUndamped plasmon modes and enhanced superconductivity in metal diborides
Author(s) -
Han Gao,
Chao Ding,
Wei Geng,
Xikui Ma,
Yangyang Li,
Mingwen Zhao
Publication year - 2021
Publication title -
new journal of physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.584
H-Index - 190
ISSN - 1367-2630
DOI - 10.1088/1367-2630/ac122e
Subject(s) - plasmon , physics , superconductivity , condensed matter physics , phonon , anisotropy , quasiparticle , work (physics) , doping , quantum mechanics
The anisotropic geometric and electronic structures of metal diborides ( M B 2 ) leads to many unusual optical and electronic properties. Here, we present a first-principles study on the low-energy collective electronic excitations and the superconducting performance of the M B 2 ( M = Be, Mg, Al, and Ca). We demonstrate the undamped cosine-like plasmon modes and the sine-like acoustic plasmons in these metal diborides. Interestingly, the energy of the acoustic plasmons shows a positive correlation with the E 2 g phonon modes which are negatively correlated with the superconducting transition temperature ( T c ) of the M B 2 materials. Moreover, hole doping can lower the energy of the acoustic plasmons and enhance the T c of CaB 2 up to 48.2 K. Our work offers a theoretical guidance to regulate the plasmonic properties, as well as a new predictive factor for superconductivity.