2008/05/30 by Shuyan Gu, Shi-Jian Gu, Junpeng Cao +6
Materials Science · Mathematics · Physics and Astronomy · #Condensed matter physics #Conductivity #Critical point (mathematics) #Electrical resistivity and conductivity #Electronic band structure #Ground state #Hubbard model #Insulator (electricity) #Iron-based superconductors research #Mathematics #Metal–insulator transition #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Superconductivity in MgB2 and Alloys #Thermodynamics #Transition point #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1140/epjb/e2008-00462-8
4 pages, 5 figures
arxiv created 2008/05/30 · openalex publication_date 2008/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The newly discovered iron-based superconductors have attracted lots of interests, and the corresponding theoretical studies suggest that the system should have six bands. In this paper, we study the multiband effects on the conductivity based on the exact solutions of one-dimensional two-band Hubbard model. We find that the orbital degree of freedom might enhance the critical value Uc of on-site interaction of the transition from a metal to an insulator. This observation is helpful to understand why undoped High-Tc superconductors are usually insulators, while recently discovered iron-based superconductors are metal. Our results imply that the orbital degree of freedom in the latter cases might play an essential role.