中国物理B ›› 2009, Vol. 18 ›› Issue (6): 2475-2480.doi: 10.1088/1674-1056/18/6/059

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Single-particle spectral function of the Hubbard chain: frustration induced

王竞1, EnricoArrigoni2   

  1. (1)Department of Physics, Fudan University, Shanghai 200433, China; Institute of Theoretical Physics and Computational Physics, Graz University of Technology, A-8010 Graz, Austria; (2)Institute of Theoretical Physics and Computational Physics, Graz University of Technology, A-8010 Graz, Austria
  • 收稿日期:2008-12-16 修回日期:2009-01-09 出版日期:2009-06-20 发布日期:2009-06-20
  • 基金资助:
    Project partly supported by the National Natural Science Foundation of China, the Ministry of Science and Technology of China (Grant No 2006CB921302), by the EC Project OFSPIN (Grant No NMP3-CT-2006-033370), by the Austrian Science Fund (Grant No FWF P18551-N16), and by the Eurasia Pacific Uninet.

Single-particle spectral function of the Hubbard chain: frustration induced

Wang Jing(王竞)a)b)† and Enrico Arrigonib)   

  1. a Department of Physics, Fudan University, Shanghai 200433, China; b Institute of Theoretical Physics and Computational Physics, Graz University of Technology, A-8010 Graz, Austria
  • Received:2008-12-16 Revised:2009-01-09 Online:2009-06-20 Published:2009-06-20
  • Supported by:
    Project partly supported by the National Natural Science Foundation of China, the Ministry of Science and Technology of China (Grant No 2006CB921302), by the EC Project OFSPIN (Grant No NMP3-CT-2006-033370), by the Austrian Science Fund (Grant No FWF P18551-N16), and by the Eurasia Pacific Uninet.

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摘要： The one-electron spectral function of a frustrated Hubbard chain is computed by making use of the cluster perturbation theory. The spectral weight we found turns out to be strongly dependent on the frustrating next-nearest-neighbor hopping t'. A frustration induced pseudogap arises when the system evolves from a gapful Mott insulator to a gapless conductor for an intermediate value of the frustration parameter |t'|. Furthermore, the opening of a pseudogap in the density of states already in the metallic side leads to a continuous opening of the true gap in the insulator. For the hole-doped case, the pseudogap is pinned at the Fermi energy, while the Mott gap is shifted in energy with increasing Hubbard interaction U. The separation of the pseudogap and Mott gap in the hole-doped system demonstrates the validity of the existence of a pseudogap.

关键词: cluster perturbation theory, pseudogap, metal-insulator transitions

Abstract: The one-electron spectral function of a frustrated Hubbard chain is computed by making use of the cluster perturbation theory. The spectral weight we found turns out to be strongly dependent on the frustrating next-nearest-neighbor hopping t'. A frustration induced pseudogap arises when the system evolves from a gapful Mott insulator to a gapless conductor for an intermediate value of the frustration parameter |t'|. Furthermore, the opening of a pseudogap in the density of states already in the metallic side leads to a continuous opening of the true gap in the insulator. For the hole-doped case, the pseudogap is pinned at the Fermi energy, while the Mott gap is shifted in energy with increasing Hubbard interaction U. The separation of the pseudogap and Mott gap in the hole-doped system demonstrates the validity of the existence of a pseudogap.

Key words: cluster perturbation theory, pseudogap, metal-insulator transitions

中图分类号:  (Electronic structure (photoemission, etc.))

  • 74.25.Jb
71.27.+a (Strongly correlated electron systems; heavy fermions) 71.30.+h (Metal-insulator transitions and other electronic transitions) 74.20.-z (Theories and models of superconducting state) 74.72.-h (Cuprate superconductors)