Structural and Electronic Properties of Insulating Materials

该奖项支持绝缘材料的结构和电子特性的基础理论研究，特别强调开发用于计算和分析这些特性的新技术。 目标是继续发展精确、高效、稳健和信息丰富的算法，用于计算复杂材料的电子结构，并将这些方法应用于研究几种重要的材料系统，特别是电介质氧化物。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，在适当的情况下使用超软赝势。 将应用和开发的新方法是那些通过与Wannier函数，电极化和对电场的响应相关的理论概念给出电子和介电性质的局部实空间图像的方法。应用将主要集中在绝缘氧化物上，无论是具有强大的应用潜力，还是具有不寻常的介电性质。 一个主要的推动力将是研究所谓的“高K”超导体，即，具有约20或更高的介电常数的绝缘氧化物可以是下一代微电子学的候选者。 第二个重点将是新发现的一类具有巨大的静态介电常数的材料。 虽然我们和其他人最近的工作往往指向这个巨大的介电响应的外在机制，也有与晶格介电响应，值得进一步研究的异常。 我们还计划通过研究GaN中的螺旋位错来继续我们之前对宽禁带III-V族半导体的兴趣。%该奖项支持材料的理论计算研究。 该研究将进一步发展新的计算技术，以更好地理解材料的电子和结构特性。 这些最先进的技术将被应用于具有不寻常的电性能的材料。 这项基础研究的成功完成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.***