Extended Hubbard model applied to study the pressure effects in high-temperature superconductors

Article

关键词: INDUCED CHARGE-TRANSFER;    ANISOTROPIC COMPRESSIBILITY;    TRANSITION-TEMPERATURE;    CARRIER CONCENTRATION;    ELECTRONIC-STRUCTURE;    TC;    DEPENDENCE;    YBA2CU3O7;    150-K;    T(C);   

DOI  :  10.1103/PhysRevB.56.466

来源: SCIE

【 摘 要 】

We make use of a BCS-type approach based on the extended Hubbard Hamiltonian to study the superconductor transition and to give a microscopic interpretation of the pressure effects on T-c in high-temperature superconductors. This method suggests that the applied pressure causes an increase of the superconducting gap and this effect is explored in order to explain the variations of T-c. Our approach is therefore beyond the scope of previous phenomenological models which basically postulate a pressure-induced charge transfer and an intrinsic term linear in pressure. We obtain a microscopic interpretation of this intrinsic term and a general expansion of T-c in terms of the pressure. To demonstrate the efficiency of the method we apply it to the experimental data of the Hg-based superconductors.

【 授权许可】

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