Pseudogap-related charge dynamics in the layered nickelate R2-xSrxNiO4 (x similar to 1)

Article

关键词: RAY-ABSORPTION;    STRIPE ORDER;    TEMPERATURE;    TRANSITION;    HEAT;    SPECTROSCOPY;    LA2-XSRXNIO4;    DEPENDENCE;    GAP;   

DOI  :  10.1103/PhysRevB.86.165126

来源: SCIE

【 摘 要 】

Charge dynamics and its critical behavior are investigated near the metal-insulator transition of layered-nickelate R2-xSrxNiO4 (R = Nd, Eu). The polarized x-ray absorption spectroscopy experiment clearly shows the multiorbital nature which enables the x(2) - y(2)-orbital-based checkerboard-type charge ordering or correlation to persist up to the critical doping region (x similar to 1). In the barely metallic region proximate to the charge-ordered insulating phase, the nominal carrier density estimated from the Hall coefficient markedly decreases in accord with development of the pseudogap structure in the optical conductivity spectrum, while the effective mass is least enhanced. The present findings combined with the results of recent angle-resolved photoemission spectroscopy show that the pseudogap in the metal-insulator critical state evolves due to the checkerboard-type charge correlation to extinguish the coherent-motion carriers in a characteristic momentum (k)-dependent manner with lowering temperature.

【 授权许可】

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