Quantitative test of a microscopic mechanism of high-temperature superconductivity

Article

关键词: ELECTRONIC SPECIFIC-HEAT;    NEUTRON-SCATTERING;    SO(5) SYMMETRY;    HUBBARD-MODEL;    YBA2CU3O7;    300-K;    GAP;   

DOI  :  10.1038/25482

来源: SCIE

【 摘 要 】

One of the main challenges to theoretical attempts to understand the microscopic mechanism of high-transition-temperature (high-T-c) superconductivity is to account quantitatively for the superconducting condensation energy, the energy by which the normal state differs from the superconducting state(1-6). A microscopic model commonly used to describe the superconducting copper oxides, the t-J model(7), is thought to capture the essential physics of the phenomenon: the interplay between the electrons' kinetic energy and their antiferromagnetic exchange interaction. Within the t-J model the condensation energy can be related to the change in the dynamical spin structure between the superconducting and the normal states(8). Here we propose a microscopic mechanism for the condensation energy of high-T-c superconductors. Within this mechanism, the appearance of a resonance in the superconducting state(9-13) enables the antiferromagnetic exchange energy in this state to be lowered relative to the normal state. We show that the intensity of the resonant neutron-scattering peak observed previously in YBa2Cu3O7 when it undergoes the transition to the superconducting state(14-16) is in quantitative agreement with the condensation energy of these materials(2,3).

【 授权许可】

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