Exact diagonalization studies on two-band minimal model for iron-based superconductors

✍ Scribed by M. Okumura; N. Nakai; H. Nakamura; N. Hayashi; S. Yamada; M. Machida

• Book ID: 104084022
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 351 KB
• Volume: 469
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2009.05.102

✦ Synopsis

In order to explore a superconducting mechanism on iron-based superconductors, we numerically study a two-band minimal model considering two degenerate d xz and d yz orbitals on Fe atom. We perform exact diagonalization on a two-band and two-leg square ladder totally composed of 10 lattice sites, which is computationally equivalent to 4-leg 20-sites square-Hubbard-ladder. Consequently, we find that a robust pairing occurs in a wide parameter range when the intra-orbital repulsive interaction becomes smaller than the inter-orbital one. Moreover, the obtained binding energy can grow into much larger value than that obtained in the single band Hubbard model depending on the parameter range.