Nesting properties and anomalous band effect in MgB2
arXiv:cond-mat/0106620 · doi:10.1143/JPSJ.70.2376
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.
15 pages, 7 graphs. to be published in J. Phys. Soc. Jpn. 70_, No.8
References in corpus (1)
Cited by in corpus (4)
- Feshbach resonances and mesoscopic phase separation near a quantum critical point in multiband FeAs-based superconductors
- Isotope effect on the E2g phonon and mesoscopic phase separation near the electronic topological transition in Mg1-xAlxB2
- Structural and Superconducting Transitions in Mg_{1-x}Al_{x}B_2
- Pressure Effects and Large Polarons in Layered MgB_2 Superconductor