First-Principles Calculation for the Electron--Phonon Coupling Constant of Superconducting MgB2
CHEN Xiang-Rong1,2, GUO Hua-Zhong1, CAI Ling-Cang3, GAO Jie4
1Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065
2International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016
3Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900
4College of Physical Science and Technology, Sichuan University, Chengdu 610065
First-Principles Calculation for the Electron--Phonon Coupling Constant of Superconducting MgB2
1Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065
2International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016
3Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900
4College of Physical Science and Technology, Sichuan University, Chengdu 610065
Abstract： We use a first-principles plane wave method with the new relativistic analytic pseudopotential of the Hartwigsen, Goedecker and Hutter (HGH) scheme and the pseudopotential of the Troullier--Martins scheme to calculate the electron--phonon coupling constant λ of superconducting MgB2. The calculated results show that there is a peak at about 300-350cm-1 in the electron--phonon spectral functional α2F(ω), duo to the coupling of the electrons to the acoustic phonon, and the relativistic effect appears in the high frequencies zone. All the results agree well with the present and previous experimental data.
2005, Vol. 22 
