Optical and Magnetic Spectroscopy of Carbon-Based Materials

*非技术摘要*这个个人研究人员奖支持一个研究项目，旨在加深我们对碳网络的理解，碳网络是一种新兴材料，具有创造革命性多功能电子产品的潜力。碳网络，包括石墨烯和碳纳米管，预计将具有迷人的电子、光学和磁性，原子排列的微小变化可以极大地改变它们的行为。随着这一领域的进步，研究人员需要越来越多的创造性工具来研究碳纳米材料的电子性质。这项工作利用了PI开创的方法，将磁性用作电子特性的非侵入性探针。例如，碳平面网络中的无序目前引起了人们的极大兴趣，因为这些区域似乎与光耦合，在碳设备中也可能有助于引导电子。已经观察到由无序引起的磁性的戏剧性变化(由网络的氧键引起)，并为将无序与这些材料的电子景观的变化联系起来提供了一个尖锐的工具。这项研究将让研究生参与协作工作，帮助他们规划成功的跨学科职业生涯。对该项目的支持将有助于扩大国家科学基金会资助的共享设备基金的外联活动，提供更多的远程实验和招募新用户。*技术摘要*这个单独的研究项目将研究源自碳的六角形网络的材料的基本光学和磁性，包括石墨烯、氧化石墨烯和碳纳米管。这项研究的很大一部分是利用轨道抗磁性与局部光学和输运性质之间的重要联系。具体地说，前者提供了单粒子电子学的补充探头，通常可以澄清后者。在氧化石墨烯中，轨道抗磁性的变化将量化芳香网络的破坏，这可能是该材料带隙工程和光学发射的关键。在碳纳米管的情况下，一组高纯度的样品将被用来理解碳纳米管中的抗磁性如何取决于对称性和原子结构。对于石墨烯，将研究由狄拉克点的量子临界性引起的磁异常的可能性。此外，一组独特的纯化碳纳米管样品将被用来提供碳纳米管暗激子能量随原子结构变化的最终图谱。这项研究将让研究生参与协作工作，帮助他们规划成功的职业生涯。对该项目的支持将有助于扩大国家科学基金会资助的共享设备基金的外联活动，提供更多的远程实验和招募新用户。

****NON-TECHNICAL ABSTRACT****This individual investigator award supports a research project that aims to deepen our understanding of carbon networks, a class of emerging materials with potential to create revolutionary multifunctional electronics. Carbon networks, including graphene and carbon nanotubes, are predicted to have fascinating electronic, optical and magnetic properties, where small changes in atomic arrangements can dramatically alter their behavior. As progress in this field moves forward, researchers need increasingly creative tools to study the electronic properties of carbon nanomaterials. This work leverages methods pioneered by the PI to use magnetism as a non-invasive probe of electronic properties. As an example, disorder in planar networks of carbon is currently of great interest because such regions appear to couple to light and may also be useful in 'steering' electrons around in carbon devices. Dramatic changes in magnetic properties induced by disorder (caused by oxygen bonding to the network) have already been observed and provide an incisive tool for relating disorder to changes in the electronic landscape of these materials. This research will involve graduate students in collaborative work that will help them chart successful interdisciplinary careers. Support for this project will enable an expansion of outreach activities at an NSF funded Shared Equipment Facility (SEF), providing additional remote experiments and recruitment of new users. ****TECHNICAL ABSTRACT****This individual investigator project will study fundamental optical and magnetic properties of materials derived from hexagonal networks of carbon, including graphene, graphene oxide, and carbon nanotubes. Much of this research exploits important connections between orbital diamagnetism and local optical and transport properties. Specifically, the former provides a complementary probe of single-particle electronics that can often clarify the latter. In graphene oxide, changes in orbital diamagnetism will quantify aromatic network disruption that may hold a key to bandgap engineering and optical emission in that material. In the case of carbon nanotubes, a battery of highly purified samples will be used to understand how diamagnetism in carbon nanotubes depends on symmetry and atomic structure. For graphene, the possibility of magnetic anomalies that arise from quantum criticality at the Dirac point will be investigated. In addition, a unique collection of purified carbon nanotube samples will be used to provide a definitive map of carbon nanotube dark exciton energies as a function of atomic structure. This research will involve graduate students in collaborative work that will help them chart successful careers. Support for this project will enable an expansion of outreach activities at an NSF funded Shared Equipment Facility (SEF), providing additional remote experiments and recruitment of new users.