Theoretical investigation of emerging electronic materials and devices

* * * * *此DG用于支持我的量子输运理论和纳米电子器件物理的研究项目，以及为新兴电子材料和器件开发强大的建模工具。长期目标是实现一个全面和通用的框架，我称之为原子-TCAD：基于原子第一原理的技术计算机辅助设计（TCAD）。该框架是在没有任何现象学和不受控制参数的情况下，利用原子第一原理定量分析实际纳米结构中电荷、自旋、谷和其他准粒子的非线性和非平衡量子输运。*** *为了实现原子式tcad，我的理论/方法发展有两个重点。(1)对于新兴电子材料的研究，将使用Kohn-Sham （KS）密度泛函理论（DFT）。然而，KS-DFT通常可以解决由几百个原子组成的问题，除非使用极端近似值。对于原子式tcad来说，必须解决这个“尺寸问题”。为此，我们将开发一种新的KS-DFT方法，名为RESCU（真实空间电子计算器），这是我们最近发明的：RESCU可以解决涉及数千到14,000个原子的材料问题，正如我们在小型计算机上测试过的那样。(2)为了研究量子输运，标准的第一原理方法是在非平衡格林函数（NEGF）框架内执行DFT，这是我们不久前发明的一种形式。我们将开发新的方法来更有效地求解NEGF-DFT方程，以便能够预测实际的器件特性。我们也将发展处理强电子-电子相关效应和分析瞬态输运性质的方法。***使用我们的方法，我们将解决许多根本有趣和实际重要的问题，包括：最近发现的Weyl拓扑半金属的量子输运特性、自旋电子学微波传感中的磁极化效应、电、光和热驱动力对谷自由度的量子输运、高频和瞬态电流、三维finfet中的应变效应、缺陷形成能量与系统尺寸的比例、高材料上新兴的碳和其他二维纳米结构、反常霍尔系数、电阻随机存取存储单元，纳米结构表面科学，扫描探针图像模拟等。我们的工作将对纳米电子器件物理学产生重大影响。*** *我的研究项目涉及量子物理、电子工程、化学和材料科学的跨学科性质，为HQP提供了良好的培训环境。要开发和使用的理论方法和建模工具是最先进的。我们与实验实验室的密切合作进一步丰富了培训内容。********

* * * * * This DG is for supporting my research program of quantum transport theory and nanoelectronic device physics, and the development of powerful modeling tools for emerging electronic materials and devices. The long term goal is to achieve a comprehensive and universal framework which I call atomistic-TCAD: for atomic first principles based technology computer aided design (TCAD). This framework is to quantitatively analyze nonlinear and non-equilibrium quantum transport of charge, spin, valley and other quasi-particles in realistic nanostructures by atomic first principles without any phenomenological and uncontrolled parameters.*** *To achieve atomistic-TCAD, my theoretical/methodological developments have two focuses. (1) For investigating emerging electronic materials, Kohn-Sham (KS) density functional theory (DFT) will be used. However, KS-DFT can typically solve problems comprising of a few hundred atoms unless using drastic approximations. This “size problem” must be solved for atomistic-TCAD. To this end, we will develop a new KS-DFT methodology named RESCU (real space electronic calculator) which we invented recently: RESCU can solve materials problems involving many thousands up to 14,000 atoms as we have tested, on small computer sources. (2) For investigating quantum transport, the standard first principles approach is by carrying out DFT within the nonequilibrium Green's function (NEGF) framework a formalism invented by us some time ago. We will develop new approaches to solve the NEGF-DFT equations much more efficiently so that realistic device properties can be predicted. We will also develop methods for handling strong electron-electron correlation effects and to analyze transient transport properties. *** Using our methodology, we shall solve many fundamentally interesting and practically important problems, including: quantum transport properties of the recently discovered Weyl topological semimetals, magnetic polariton effects in microwave sensing by spintronics, quantum transport of the valley degrees of freedom by electrical, optical and thermal driving forces, high frequency and transient currents, strain effects in 3D FinFETs, the scaling of defect formation energy versus system size, emerging carbon and other 2D nanostructures on high- materials, anomalous Hall coefficients, resistive random access memory cells, surface science for nanostructures and scanning probe image simulations, etc. Our work will provide substantial impact to nanoelectronic device physics.*** *My research program provides excellent training environment for HQP due to its interdisciplinary nature involving quantum physics, electronic engineering, chemistry and materials science. The theoretical methods and modeling tools to be developed and used are state-of-the-art. The training is further enriched by our close collaborations with experimental labs.********