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arXiv 0704.0327cond-mat.str-elcond-mat.mtrl-sci
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从关联金属相到能带绝缘相的演化

Evolution of a band insulating phase from a correlated metallic phase

Kalobaran Maiti, Ravi Shankar Singh, V. R. R. Medicherla

摘要:

利用高分辨光电子能谱研究了SrRu_(1-x)Ti_xO_3中电子结构随x的变化,其中SrRuO_3是弱关联金属,SrTiO_3是能带绝缘体.表面光谱表现出金属-绝缘体转变在x = 0.5通过打开一个软间隙。硬间隙出现在较高的x值与运输性能一致。与此相反,体光谱显示在费米能级的赝能隙,和不寻常的演化表现出明显的加宽的相干特征和随后的强度降低的较低的哈伯德带与x的增加。有趣的是,第一原理的方法被发现是足够的捕获在高能量尺度的异常演化。光谱线形的分析表明,在这个系统的电子性质的无序和电子关联之间的强烈相互作用。

英文摘要:

We investigate the evolution of the electronic structure in SrRu_(1-x)Ti_xO_3 as a function of x using high resolution photoemission spectroscopy, where SrRuO3 is a weakly correlated metal and SrTiO3 is a band insulator. The surface spectra exhibit a metal-insulator transition at x = 0.5 by opening up a soft gap. A hard gap appears at higher x values consistent with the transport properties. In contrast, the bulk spectra reveal a pseudogap at the Fermi level, and unusual evolution exhibiting an apparent broadening of the coherent feature and subsequent decrease in intensity of the lower Hubbard band with the increase in x. Interestingly, the first principle approaches are found to be sufficient to capture anomalous evolutions at high energy scale. Analysis of the spectral lineshape indicates strong interplay between disorder and electron correlation in the electronic properties of this system.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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