Effective inter-band coupling in MgB2 due to anharmonic phonons
| dc.creator | Acquarone, M. | |
| dc.creator | Romano', L. | |
| dc.date | 2003-02-14 | |
| dc.date.accessioned | 2026-07-07T02:49:40Z | |
| dc.date.available | 2026-07-07T02:49:40Z | |
| dc.description | We investigate the origin of the inter-band coupling in MgB2 by focusing on its unusual phononic features, namely, the strong anharmonicity of the phonons and the presence of both linear and quadratic electron-phonon interactions of the Su-Schrieffer-Heeger (SSH) type. The bare electronic Hamiltonian has two bands with intra- and inter-band hopping, which lead to two decoupled hybridized bands. The phonon Hamiltonian including the anharmonic terms is diagonalized approximately by a squeezing transformation, which causes the softening of the phonon frequency. The linear SSH coupling amplitude is reduced, consistently with the estimates from first-principle calculations. Additionally, the quadratic coupling generates an effective phonon-induced interaction between the hybridized bands, which is non-vanishing even in the limit of vanishing inter-bare-band hopping amplitude. | |
| dc.description | 11 pages | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0302303 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0302303 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/20889 | |
| dc.subject | Superconductivity | |
| dc.title | Effective inter-band coupling in MgB2 due to anharmonic phonons | |
| dc.type | text |