Nanoscale Physics

我的研究计划旨在对纳米结构的物理学有一个基本的了解，纳米结构是尺寸从大约一纳米到几百纳米的系统。纳米结构的性质既不同于单个原子，也不同于宏观的日常物体。它们在从信息处理到医学的各种应用中的重要性得到了广泛的认可。拟议的研究将在这一总主题中有一些重点：我们将在先前成功阐明石墨烯纳米结构的传输特性的基础上再接再厉，包括几纳米宽的碳原子纳米带和一个单原子层厚的纳米带。我们将把这项研究带到一个新的方向，这是因为最近令人惊讶的实验发现，在碳化硅衬底上，一些长达16微米的石墨烯纳米带在室温下表现出接近e2/h的电导。我们将研究可能的机制(包括铁磁性，结构应变，由于与碳化硅的相互作用而增强的自旋-轨道耦合，以及拓扑保护)，可能导致这种尚未解释的效应。我们将把这项研究进一步扩展到过渡金属二卤化物纳米结构，其强烈的自旋-轨道耦合可能导致拓扑保护的电子和自旋电子性质。目前，许多探索从铁磁体注入半导体的自旋注入的实验与理论之间存在着数量级的分歧。我们将进行计算机模拟，以解决这一根本冲突。我们将继续我们对单分子纳米磁体的理论研究，这些磁体可能会在高密度磁存储器或量子信息处理中得到应用。实验人员最近已经开始成功地将单分子磁体插入电路中，假定不会损坏分子，并测量得到的设备的传输特性。新的实验数据将帮助我们发展单分子纳米磁性晶体管电荷和自旋输运的现实基础理论。我们还将继续我们的工作，旨在了解单分子电子和自旋电子器件中分子和电极之间的界面。这一努力的目的是获得对这些界面结构的原子尺度控制，这是实际设备应用所需的，以及确定这些系统中传输理论与实验的基准。这项拟议的研究预计将实现对新型纳米系统的更好理解，并将培训学生和博士后从事与纳米科学前沿实验密切相关的开创性基础理论研究，纳米科学是一个具有巨大且迅速增长的科学和技术重要性的领域。它可能会促进新技术的创造，使加拿大受益。

My research program is directed at obtaining a fundamental understanding of the physics of nanostructures, systems with dimensions ranging from about a nanometer to a few hundred nanometers. Nanostructures have properties that differ from those of both individual atoms and macroscopic everyday objects. Their importance for applications ranging from information processing to medicine is widely recognized. The proposed research will have a number of foci within this general theme: We will build on our previous successes elucidating the transport properties of graphene nanostructures, including nanoribbons of carbon atoms several nanometers wide and a single atomic layer thick. We will take this research in a new direction, prompted by the recent surprising experimental discovery that some graphene nanoribbons as long as 16 micrometers on SiC substrates exhibit conductances near e2/h up to room temperature. We will investigate possible mechanisms (including ferromagnetism, structural strains, enhanced spin-orbit coupling due to interactions with the SiC, and topological protection) that may give rise to this as yet unexplained effect. We will extend this research further to transition metal dichalcogenide nanostructures whose strong spin-orbit coupling may result in topologically protected electronic and spintronic properties. There is currently orders of magnitude disagreement between many experiments probing spin injection from ferromagnets into semiconductors and theory. We will carry out computer simulations to resolve this fundamental conflict. We will continue our theoretical studies of single-molecule nanomagnets that may find applications as high density magnetic memories or in quantum information processing. Experimentalists have recently begun to successfully insert single-molecule magnets into electric circuits putatively without damaging the molecule, and measuring the transport properties of the resulting devices. The new experimental data will help us develop realistic fundamental theories of charge and spin transport through single molecule nanomagnet transistors. We will also continue our work aimed at understanding the interfaces between the molecule and electrodes in single-molecule electronic and spintronic devices. This effort is aimed at gaining atomic scale control of the structures of these interfaces which is needed for practical device applications as well as for definitively benchmarking theories of transport in these systems against experiment. The proposed research is expected to achieve a better understanding of novel nanoscale systems and will train students and postdocs to do pioneering fundamental theoretical research closely linked to cutting edge experiments in nanoscience, a field of huge and rapidly growing scientific and technological importance. It may facilitate creation of new technologies that benefit Canada.