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arXiv 1307.4352cond-mat.str-elcond-mat.mtrl-sci
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LaAlO3/SrTiO3界面金属-绝缘体转变的再探讨:混合功能研究

Metal-insulator transition at the LaAlO3/SrTiO3 interface revisited: A hybrid functional study

F. Cossu, U. Schwingenschlögl, V. Eyert

摘要:

采用密度泛函理论研究了LaAlO 3/SrTiO 3界面的电子性质。与以前的研究,这依赖于(半)本地泛函和GGA+U方法,我们在这里使用最近开发的混合泛函来确定电子结构。这种方法提供了一个无参数的平等的基础上访问金属和绝缘多层膜的明显优势。与基于半局部GGA泛函的计算相比,我们的混合泛函计算导致绝缘系统的带隙大大增加。的电子结构的细节显示出从GGA计算得到的实质性偏差。这使人们对以前基于半局部泛函的所有结果产生了严重的怀疑。特别是,使用刚性带位移(“剪刀算子”)的校正不能导致有效的结果。

英文摘要:

We investigate the electronic properties of the LaAlO3/SrTiO3 interface using density functional theory. In contrast to previous studies, which relied on (semi-)local functionals and the GGA+U method, we here use a recently developed hybrid functional to determine the electronic structure. This approach offers the distinct advantage of accessing both the metallic and insulating multilayers on a parameter-free equal footing. As compared to calculations based on semilocal GGA functionals, our hybrid functional calculations lead to a considerably increased band gap for the insulating systems. The details of the electronic structure show substantial deviations from those obtained by GGA calculations. This casts severe doubts on all previous results based on semilocal functionals. In particular, corrections using rigid band shifts ("scissors operator") cannot lead to valid results.

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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