Structural and Electronic Properties of Insulating Materials

该奖项支持对绝缘材料的结构和电子性质的基础理论研究，特别强调开发用于计算和分析这些性质的新技术。其目标是继续开发精确、高效、健壮和信息丰富的算法来计算复杂材料的电子结构，并将这些方法应用于研究几个重要的材料系统，特别是介电氧化。计算工作的背景将主要是密度泛函理论的平面波赝势方法，并在适当的情况下使用超软赝势。将应用和开发的新方法是通过与Wannier函数、电极化和电场响应相关的理论概念来提供电子和介电性质的局部真实空间图像的方法。应用将主要集中在具有很强应用潜力的或具有特殊介电性质的绝缘氧化物上。主要的推力将是研究所谓的“高K”介质，即介电常数约为20或更高的绝缘氧化物，可能是下一代微电子学的候选者。第二个重点将放在一类新发现的材料上，这些材料具有巨大的静态介电常数。虽然我们和其他人最近的工作倾向于指出这种巨大的介电响应的外部机制，但也有一些与晶格介电响应相关的反常现象值得进一步研究。我们还计划通过研究GaN中的螺位错来继续我们以前对宽禁带III-V半导体的兴趣。该奖项支持材料的理论计算研究。这项研究将进一步开发新的计算技术，以更好地了解材料的电子和结构性质。然后，这些最先进的技术将被应用于具有不寻常电学特性的材料。成功完成这项基础研究将产生新的计算方法，并更好地了解微电子行业感兴趣的材料特性。

This award supports fundamental theoretical research on the structural and electronic properties of insulating materials, with special emphasis on development of novel techniques for the computation and analysis of these properties. The objectives are to continue the development of accurate, efficient, robust and informative algorithms for computing the electronic structure of complex materials, and to apply these methods to study several important material systems, especially dielectric oxides.The context of the computational work will primarily be the plane-wave pseudupotential approach to density-functional theory, with the use of ultrasoft pseudopotentials where appropriate. The novel methodologies that will be applied and developed are ones that give a local real-space picture of electronic and dielectric properties via theoretical concepts connected with Wannier functions, electric polarization, and response to electric fields.Applications will be focused mainly on insulating oxides, either having strong potential for applications, or else having unusual dielectric properties. A primary thrust will be to study so-called "high-K" dielectrics, i.e., insulating oxides having dielectric constants about 20 or higher that could be candidates for the next generation of microelectronics. A secondary emphasis will be on a newly discovered class of materials having enormous static dioelectric constants. While recent work by ourselves and others tends to point to an extrinsic mechanism for this enormous dielectric response, there are also anomalies associated with the lattice dielectric response that deserve further investigation. We also plan to carry forward our previous interests in wide-gap III-V semiconductors by studying screw dislocation in GaN.%%%This award supports theoretical computational research on materials. The reserach will further develop novel computational techniques to better understand the electronic and structural properties of materials. These state-of-the-art techniques will then be applied to materials having unusual electrical properties. Successful completion of this fundamental research will yield new computational methods and a better understanding of materials properties of interest to the microelectronics industry.***