标题: | 原子分子接面的自旋与非自旋电子与热流输运性质与热电效应 Spin-Polarized and Unpolarized Electron and Thermal Transport and Thermoelectricity in Atomic/Molecular Junctions |
作者: | 陈煜璋 Chen Yu-Chang 国立交通大学电子物理学系(所) |
关键字: | 密度泛函理论;平衡态电子量子输运理论;分子电子学;自旋电子学;热电效应;量子噪音;电声子交互作用;Density functional theory;Non-equilibrium quantum transport;Molecular electronics;Sprintronics;Thermopower;Shot noise;electron-phonon interactions |
公开日期: | 2012 |
摘要: | 本研究计画以第一原理计算方式,研究原子分子接面的电子与热流的非平衡态量子输运性质。主要的研究方法是在密度泛函理论与非平衡态输运理论(DFT + Lippmann-Schwinger equation)的计算架构下,结合多体物理理论,探讨分子接面系统的量子输运性质与所伴随的多体物理现象。奈米接面的模型是由两个半平面无穷大的电极与中间所夹由原子或分子所构成。其中电极部分是以凝胶模型为基础透过自洽运算求解,偏压则是由左右电极的化学位所决定。从左与右侧电极入射的电子,被中间所夹的原子或分子所散射,此效应则是在DFT + Lippmann-Schwinger equation的架构下做自洽计算得到。 我们的研究子题包含原子分子接面的 (1) 电流电压特征曲线 (2) 闸极偏压可调控之电流(电晶体元件)性质 (3)的热传导性质(以分子动力学方式模拟) (4) 电子遂穿所引起的力 (5) 量子噪音 (6) 高阶电流的相关函数关系的量子干涉行为 (7) 穿遂电子造成分子振动所造成的奈米结构局域温度上升效应 (8) 非弹性散射电子穿隧电流电压频谱 (9) 热电效应与热能电能转换机制 (10) 新型态的热电元件例如致冷机以及利用废热驱动分子电晶体的理论模型 (11) 电子与分子振动交互作用对以上问题的影响。我们目前的模型与理论计算,已经能够处理上述之研究子题。原子和分子接面的电子输运物理的特性和电极所夹的奈米结构有关,个别原子和分子的特性决定大部分的输运性质。所以本计画将在既有的基础上,继续深入研究不同的原子和分子接面系统与上述子题相关的量子输运性质。 过去十年,分子电子学和自旋电子学各自平行发展,成为物理与跨领域科学重要的研究课题。本计画的另一个主要目标则是结合这两个领域,朝着分子自旋电子学方向迈进。在现有分子电子学的基础上,引进电子自旋与自旋轨道偶合,开发新程式和新理论架构,研究原子和分子自旋轨道偶合夹在铁磁电极中间的自旋电子输运性质。因为分子元件的微小特性有助于保存传输电子的自旋,所以分子自旋电子学将来有潜力形成一个新颖且重要的前瞻性研究领域。 We propose to investigate the quantum transport properties in atomic-scale junctions in the framework of the combination of density-functional theory and Lippmann-Schwinger equation in scattering approaches. We will focus on the current-induced many-body effects in the nanoscale junctions (modeled as electron jellium) formed by atoms/molecule sandwiched between bimetallic electrodes with semi-infinite planar surface. These effects can be calculated from the wavefunctions obtained self-consistently first principles approaches allied to many-body theory. Our research will cover the following subtopics: (1) nonlinear current-voltage characteristics; (2) gate-controllable current in single-molecule transistors; (3) thermal current (simulated by MD); (4) current-induced force; (5) shot noise; (6) counting statistics; (7) local heating; (8) inelastic electron tunneling spectroscopy (IETS); (9) thermoelectricity and the energy-conversing mechanism between thermal and electric current; (10) new forms of atomic-scale thermoelectric devices, such and nano-refrigerators, power generators, and self-powered electronic nano-devices; and (11) the effects of electron-vibration interactions on the above mentioned subtopics. In the past decade, we have developed theories and codes to address the above-mentioned subtopics. Owing to the wave nature, the species of individual atom and molecule are critically important to the quantum transport properties in the nanojunctions. We, thus, will continue to investigate the transport properties relevant to the above-mentioned subtopics in various atomic and molecular junctions.Molecular electronics and spintronics emerged around 10 years ago. Both have become the forefront of the multidisciplinary fundamental researches including physics. The alternative major goal of this project is to bridge the gap between molecular electronics and spintronics. We will develop new theories and codes including the ferromagnetic electrodes and spin-orbit potential in the nano-structured object based on our knowledge in molecular electronics to advance the field of ’molecular spintronics.’ |
官方说明文件#: | NSC100-2112-M009-012-MY3 |
URI: | http://hdl.handle.net/11536/98714 https://www.grb.gov.tw/search/planDetail?id=2391544&docId=380363 |
显示于类别: | Research Plans |