Single-particle spectral function of the Hubbard chain: frustration induced
Wang Jinga, Enrico Arrigonib
a Department of Physics, Fudan University, Shanghai 200433, China; Institute of Theoretical Physics and Computational
Physics, Graz University of Technology, A-8010 Graz, Austria; b Institute of Theoretical Physics and Computational
Physics, Graz University of Technology, A-8010 Graz, Austria
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.
Received: 16 December 2008
Revised: 09 January 2009
Published: 20 June 2009
Fund: 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.
Cite this article:
Wang Jing, Enrico Arrigoni Single-particle spectral function of the Hubbard chain: frustration induced 2009 Chin. Phys. B 18 02475
