Nesting properties and anomalous band effect in MgB2
Abstract
First principle FLAPW band calculations of the new superconductor MgB2 were performed and the polarization function P12(Q) between the two p-bands mainly formed of boron pz-orbital was calculated. We found that P12(Q) is substantially enhanced around Q=(0,0,p/c), which supports the two-band mechanism of superconductivity for MgB2. P12(Q) peaks at Qz ~ 0.3(2p/c) and Qz \~ 0.5(2p/c). These two peaks are related to the nesting of these Fermi surfaces, but significantly deviates from the position expected from the simplest tight-binding bands for the p-bands. From the calculations for different lattice parameters, we have found significant dependences on the isotopic species of B and on the pressure effect of the polarization function in accordance with the respective changes of Tc in the above-mentioned framework.
Keywords
Cite
@article{arxiv.cond-mat/0106620,
title = {Nesting properties and anomalous band effect in MgB2},
author = {Izumi Hase and Kunihiko Yamaji},
journal= {arXiv preprint arXiv:cond-mat/0106620},
year = {2009}
}
Comments
15 pages, 7 graphs. to be published in J. Phys. Soc. Jpn. 70_, No.8