Spectral functions, Fermi surface, and pseudogap in the t-J model

Article

关键词: UNDERDOPED CUPRATE SUPERCONDUCTORS;    HIGH-TEMPERATURE SUPERCONDUCTIVITY;    ANGLE-RESOLVED PHOTOEMISSION;    ELECTRONIC SPECIFIC-HEAT;    C SUPERCONDUCTORS;    HUBBARD-MODEL;    DOPED ANTIFERROMAGNETS;    CORRELATED ELECTRONS;    GREENS-FUNCTION;    NORMAL-STATE;   

DOI  :  10.1103/PhysRevB.65.174529

来源: SCIE

【 摘 要 】

Spectral functions within the generalized t-J model as relevant to cuprates are analyzed using the method of equations of motion for projected fermion operators. In the evaluation of the self-energy a decoupling of spin and single-particle fluctuations is performed. It is shown that in an undoped antiferromagnet the method reproduces the self-consistent Born approximation. For finite doping with short-range antiferromagnetic order the approximation evolves into a paramagnon contribution which retains a large incoherent contribution in the hole part of the spectral function as well as the hole-pocket-like Fermi surface at low doping. On the other hand, the contribution of longer-range spin fluctuations, with the coupling mostly determined predominantly by J and next-neighbor hopping t', is essential for the emergence of the pseudogap. The latter shows, at low doping in the effective truncation of the large Fermi surface, a reduced electron density of states and at the same time a quasiparticle density of states at the Fermi level.

【 授权许可】

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