pi excitation of the t-J model

Article

关键词: HIGH-TEMPERATURE SUPERCONDUCTORS;    RESONANT NEUTRON-SCATTERING;    HUBBARD-MODEL;    CUPRATE SUPERCONDUCTORS;    COLLECTIVE MODES;    ORDER-PARAMETER;    SO(5) SYMMETRY;    NEGATIVE-U;    YBA2CU3O6+X;    PEAK;   

DOI  :  10.1103/PhysRevB.58.5719

来源: SCIE

【 摘 要 】

In this paper, we present analytical and numerical calculations of the pi resonance in the t-J model. We show in detail how the pi resonance in the particle-particle channel couples to the dynamical spin correlation function in a superconducting state. The contribution of the pi resonance to the spin excitation spectrum can be estimated from general model-independent sum rules, and it agrees with our detailed calculations. The results are in overall agreement with the exact diagonalization studies of the t-J model. Earlier calculations predicted the correct doping dependence of the neutron resonance peak in the YBa2CU3O6+x superconductor, and in this paper detailed energy and momentum dependence of the spin correlation function is presented. The microscopic equations of motion obtained within current formalism agree with that of the SO(5) nonlinear sigma model, where the pi resonance is interpreted as a pseudo-Goldstone mode of the spontaneous SO(5) symmetry breaking.

【 授权许可】

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