Open AccessSuperconductivity in Bismuth. A New Look at an Old Problem
Author(s) -
Zaahel Mata-Pinzón,
Ariel A. Valladares,
R.M. Valladares,
Ariel A. Valladares
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0147645
Subject(s) - bismuth , superconductivity , amorphous solid , condensed matter physics , fermi level , atom (system on chip) , fermi energy , physics , pair distribution function , topology (electrical circuits) , materials science , chemistry , quantum mechanics , crystallography , electron , mathematics , combinatorics , computer science , embedded system , metallurgy
To investigate the relationship between atomic topology, vibrational and electronic properties and superconductivity of bismuth, a 216-atom amorphous structure ( a-Bi 216) was computer-generated using our undermelt-quench approach. Its pair distribution function compares well with experiment. The calculated electronic and vibrational densities of states (eDOS and vDOS, respectively) show that the amorphous eDOS is about 4 times the crystalline at the Fermi energy, whereas for the vDOS the energy range of the amorphous is roughly the same as the crystalline but the shapes are quite different. A simple BCS estimate of the possible crystalline superconducting transition temperature gives an upper limit of 1.3 mK. The e-ph coupling is more preponderant in a-Bi than in crystalline bismuth ( x-Bi ) as indicated by the λ obtained via McMillan’s formula, λ c = 0.24 and experiment λ a = 2.46. Therefore with respect to x-Bi , superconductivity in a-Bi is enhanced by the higher values of λ and of eDOS at the Fermi energy.