Theoretical investigation of emerging electronic materials and devices

* * * * * 这个DG是为了支持我的量子输运理论和纳米电子器件物理的研究计划，并为新兴的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唯象和不可控参数的情况下，通过原子第一性原理定量分析真实纳米结构中电荷、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TCAD，我的理论/方法论发展有两个重点。(1)为了研究新兴的电子材料，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。原子TCAD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，命名为RESCU（真实的空间电子计算器），我们最近发明的：RESCU可以解决材料问题，涉及成千上万多达14,000个原子，我们已经测试，在小型计算机源。(2)对于研究量子输运，标准的第一性原理方法是在非平衡绿色函数（NEGF）框架内进行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解决NEGF-DFT方程，以便可以预测实际的器件特性。我们还将开发处理强电子-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，我们将解决许多基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性质，通过自旋电子学的微波传感中的磁极化子效应，通过电、光和热驱动力的谷自由度的量子输运，高频和瞬态电流，3D FinFET中的应变效应，缺陷形成能与系统尺寸的比例关系，高材料上出现的碳和其他二维纳米结构，反常霍尔系数，电阻随机存取存储器单元，纳米结构的表面科学和扫描探针图像模拟等，我们的工作将对纳米电子器件物理产生重大影响。 * 我的研究项目为HQP提供了良好的培训环境，因为它涉及量子物理，电子工程，化学和材料科学的跨学科性质。开发和使用的理论方法和建模工具是最先进的。通过与实验室的密切合作，培训得到了进一步的丰富。*

* * * * * 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.********