Fermiology of Sr4V2O6Fe2As2: Quasi-Nested Fe vs Mott-Insulating V Orbitals

T. Qian; N. Xu; Y. -B. Shi; K. Nakayama; P. Richard; T. Kawahara; T. Sato; T. Takahashi; M. Neupane; Y. -M. Xu; X. -P. Wang; G. Xu; X. Dai; Z. Fang; P. Cheng; H. -H. Wen; H. Ding

arXiv · 1008.4905

Fermiology of Sr4V2O6Fe2As2: Quasi-Nested Fe vs Mott-Insulating V Orbitals

T. Qian·N. Xu·Y. -B. Shi·K. Nakayama·P. Richard·T. Kawahara·T. Sato·T. Takahashi·M. Neupane·Y. -M. Xu·X. -P. Wang·G. Xu·X. Dai·Z. Fang·P. Cheng·H. -H. Wen·H. Ding

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Abstract

We have performed an angle-resolved photoemission spectroscopy study of a new iron-based superconductor Sr4V2O6Fe2As2. While V 3d orbitals are found to be in a Mott insulator state and show an incoherent peak at ~ 1 eV below the Fermi level, the dispersive Fe 3d bands form several hole- and electron-like Fermi surfaces (FSs), some of which are quasi-nested by the (pi, 0) wave vector. This differs from the local density approximation (LDA) calculations, which predict non-nested FSs for this material. However, LDA+U with a large effective Hubbard energy U on V 3d electrons can reproduce the experimental observation reasonably well. The observed fermiology in superconducting Sr4V2O6Fe2As2 strongly supports that (pi, 0) interband scattering between quasi-nested FSs is indispensable to superconductivity in pnictides.

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T. Qian, N. Xu, Y. -B. Shi, K. Nakayama, P. Richard, T. Kawahara, T. Sato, T. Takahashi, M. Neupane, Y. -M. Xu, X. -P. Wang, G. Xu, X. Dai, Z. Fang, P. Cheng, H. -H. Wen, H. Ding. 2010-08-29. Fermiology of Sr4V2O6Fe2As2: Quasi-Nested Fe vs Mott-Insulating V Orbitals. https://arxiv.org/abs/1008.4905

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