Ab initio study on pressure-induced change of effective Coulomb interaction in superconducting yttrium

• Ab initio lattice dynamics based on linear response method are performed for high pressure phase of yttrium to describe electron-phonon coupling and subsequent superconducting behavior. The critical temperature T-c in fcc-Y increases monotonically with pressure up to 9.25 K at 31 GPa, which is quantitatively in excellent agreement with two quasihydrostatic experiments and is qualitatively compatible with recent experiments. The excellent agreement with experiments gives us a better understanding of the effective pseudopotential mu(*) as well as spectral function alpha(2)(omega)F(omega) in yttrium. These results demonstrate that there exists strong electron-phonon coupling in Y within the studied pressure regime, and for lower pressure electron correlation becomes stronger. Generally, it is found that superconductivity in yttrium under pressure can be described quantitatively within standard theory of phonon-mediated superconductivity.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

ab initio calculations

Coulomb blockade

electron-phonon interactions

pseudopotential methods

solid-state phase transformations

superconducting transition temperature

yttrium

generalized gradient approximation

strong-coupled superconductors

transition-temperature

metals

atoms

Physics

Fysik

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)