- 초전도 $Sr_2VO_3FeAs$에서 상관효과
- ㆍ 저자명
- 이관우,Lee. K.W.
- ㆍ 간행물명
- Progress in superconductivity
- ㆍ 권/호정보
- 2010년|12권 1호|pp.46-50 (5 pages)
- ㆍ 발행정보
- 한국초전도학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
In the superconducting $Sr_2VO_3FeAs$, containing bimetallic layers, with maximum $T_c{approx};46;K$ correlation effects on V ions have been investigated using LDA+U method. Within the local density approximation (LDA) this system has the one-third filled $t_{2g}$ manifold of V, decomposed into $d_{xy}$ of bandwidth W=2 eV and nearly degenerate $d_{zx}d_{yz}$ of W=1 eV. Consideration of correlation effects leads to a metal-insulator transition on V ions $t^{2uparrow}_{2g};{ ightarrow};d^{1uparrow}_{xz};d^{1uparrow}_{yz}$ at the critical on-site Coulomb repulsion $U_c$= 3.5 eV. At U=4 eV, the electronic structure, in which V ions are insulating, leads to several van Hove singularities near $E_F$ and similar Fermiology with other pnictides. Applying U to V ions results in increasing Fe moment as well as V moment, indicating somewhat hybridization between Fe and V ions even though this system is strongly 2-dimesional. Our results show possible importance of correlation effects on this system.