Van Hove features in Bi2Sr2CaCu2O8+delta and effective parameters for Ni impurities inferred from STM spectra

Article

关键词: LOCAL ELECTRONIC-STRUCTURE;    ANGLE-RESOLVED PHOTOEMISSION;    D-WAVE SUPERCONDUCTOR;    T-C SUPERCONDUCTOR;    VANHOVE SINGULARITY;    STATES;    SPECTROSCOPY;    DEFECTS;    PROBE;    ATOMS;   

DOI  :  10.1103/PhysRevB.66.060504

来源: SCIE

【 摘 要 】

We present a detailed quantitative comparison between theoretical calculations of the local density of states and recent experimental measurements of scanning tunneling spectra around Ni impurities in Bi2Sr2CaCu2O8+delta. A double-peak structure on the hole side of the spectrum at the Ni site is identified as the spin-split Van Hove singularity in the band structure. The Ni atom induces local changes in hopping matrix elements comparable in size to the induced on-site spin-dependent potential. We find evidence from the measurements of order-parameter suppression in the vicinity of the Ni impurity. These extracted impurity parameters can be of use in quantitative calculations of macroscopic response properties, such as the ac conductivity.

【 授权许可】

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