Effect of impurity substitution on band structure and mass renormalization of the correlated FeTe0.5Se0.5 superconductor

Article

关键词: INITIO MOLECULAR-DYNAMICS;    TOTAL-ENERGY CALCULATIONS;    IRON;    TRANSITION;    LIFEAS;    NI;    CO;   

DOI  :  10.1103/PhysRevB.93.205143

来源: SCIE

【 摘 要 】

Using angle-resolved photoemission spectroscopy (ARPES), we studied the effect of the impurity potential on the electronic structure of FeTe0.5Se0.5 superconductor by substituting 10% of Ni for Fe, which leads to an electron doping of the system. We could resolve three hole pockets near the zone center and an electron pocket near the zone corner in the case of FeTe0.5Se0.5, whereas only two hole pockets near the zone center and an electron pocket near the zone corner are resolved in the case of Fe0.9Ni0.1Te0.5Se0.5, suggesting that the hole pocket having predominantly the xy orbital character is very sensitive to the impurity scattering. Upon electron doping, the size of the hole pockets decreases and the size of the electron pockets increases as compared to the host compound. However, the observed changes in the size of the electron and hole pockets are not consistent with the rigid-band model. Moreover, the effective mass of the hole pockets is reduced near the zone center and of the electron pockets is increased near the zone corner in the doped Fe0.9Ni0.1Te0.5Se0.5 as compared to FeTe0.5Se0.5. We refer these observations to the changes of the spectral function due to the effect of the impurity potential of the dopants.

【 授权许可】

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