title: Giant anharmonicity and nonlinear electron-phonon coupling in MgB2: a combined first-principles calculation and neutron scattering study.
abstract: First-principles calculations of the electronic band structure and lattice dynamics for the new superconductor MgB (2) are carried out and found to be in excellent agreement with our inelastic neutron scattering measurements. The numerical results reveal that the E(2g) in-plane boron phonons near the zone center are very anharmonic and strongly coupled to the planar B sigma bands near the Fermi level. This giant anharmonicity and nonlinear electron-phonon coupling is key to quantitatively explaining the observed high T(c) and boron isotope effect in MgB (2).
authors.affiliation: NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: T
authors.initials: T
authors.lastname: Yildirim
authors.forename: O
authors.initials: O
authors.lastname: Gülseren
authors.forename: J W
authors.initials: JW
authors.lastname: Lynn
authors.forename: C M
authors.initials: CM
authors.lastname: Brown
authors.forename: T J
authors.initials: TJ
authors.lastname: Udovic
authors.forename: Q
authors.initials: Q
authors.lastname: Huang
authors.forename: N
authors.initials: N
authors.lastname: Rogado
authors.forename: K A
authors.initials: KA
authors.lastname: Regan
authors.forename: M A
authors.initials: MA
authors.lastname: Hayward
authors.forename: J S
authors.initials: JS
authors.lastname: Slusky
authors.forename: T
authors.initials: T
authors.lastname: He
authors.forename: M K
authors.initials: MK
authors.lastname: Haas
authors.forename: P
authors.initials: P
authors.lastname: Khalifah
authors.forename: K
authors.initials: K
authors.lastname: Inumaru
authors.forename: R J
authors.initials: RJ
authors.lastname: Cava