Thermal Transport and Thermodynamic Properties of Graphene at Very Low Temperatures

***技术摘要****本项目探索石墨烯在10mK至10K的低温热力学性质。重点是测量相关的热导通道，电子扩散，声子发射和光子发射；这项研究将产生对电子热容的灵敏测量。这项工作将通过开发宽带噪声测温技术来完成，该技术利用非常敏感的、接近量子限制的微波探测系统，可以探索不同衬底（SiO2、BN等）上的石墨烯和悬浮薄片之间的差异。另一个重要的目标是石墨烯作为超灵敏的测热计和量热计的潜在用途。初步估计表明，该材料和测量系统将能够探测单微波光子和光子散粒噪声；这些能力将在量子测量和量子信息领域产生许多机会。该项目将对一名初级科学家（博士生或博士后）的培训至关重要，并将涉及暑期本科生。PI还将与纳瓦霍民族联系，寻求一名本科生的参与。****非技术摘要****石墨烯是晶体碳的单原子层，即铅笔中的一层石墨。自2004年发现如何容易地分离这种材料以来，人们一直在努力探索其卓越的电气、机械和热性能。在这项工作中，测量是为了发现热量是如何在材料中传递的，并确定一个微小薄片的热容量。它还探索了使用微小的微米大小的石墨烯薄片作为非常敏感的辐射热计。辐射热计是一种传感器，它将光或微波形式的能量转换成热量，然后检测到这种加热。辐射热计已经被用来提供非常灵敏的大爆炸辐射探测器，未来的天文学任务将需要更灵敏的辐射热计。从估计来看，石墨烯似乎可以用来制造下一代辐射计，这项研究将确定这是否属实。这些实验将由一名初级科学家（博士后的博士生）领导，也将涉及暑期本科生。该小组将向纳瓦霍民族寻求一名本科生的参与。

***Technical Abstract****This project explores the low temperature thermodynamic properties of graphene from 10mK to 10K. The focus is on measurements of the relevant thermal conductance channels, electron diffusion, phonon emission, and photon emission; this research will produce sensitive measurements of the electronic heat capacity. The work will be accomplished through the development of wide-bandwidth noise thermometry utilizing very sensitive, nearly quantum-limited microwave detection systems allowing to explore the difference between graphene on various substrates (SiO2, BN, etc.) and suspended flakes. Another important goal is the potential use of graphene as an ultra-sensitive bolometer and calorimeter. The initial estimates suggest that this material and measurement system will be capable of detecting single microwave photons and the photon shot noise; these capabilities would produce many opportunities in the fields of quantum measurement and quantum information. This project will be essential to the training of one junior scientist (Phd student or postdoc) and will involve summer undergraduate students. The PI will also reach out to the Navajo Nation to seek the involvement of an undergraduate student.****Non-Technical Abstract****Graphene is a single atomic layer of crystalline carbon, i.e. one layer of graphite from your pencil. Since 2004 when it was discovered how to easily isolate this material, there has been an intense effort to probe the remarkable electrical, mechanical, and thermal properties. In this work, measurements are made to find how heat is transported in the material and to determine the heat capacity of a tiny flake. It also explores the use of a tiny micron-sized flake of graphene as a very sensitive bolometer. A bolometer is a sensor which converts energy in the form of light or microwaves, into heat, and then this heating is detected. Bolometers have been used to provide very sensitive probes of the radiation from the big bang and future astronomy missions will require even more sensitive bolometers. From estimates, it appears that graphene can be used to create this next generation bolometer, and this study will determine if this is indeed true. These experiments will be lead by a junior scientist (Phd student of postdoc) and will also involve summer undergraduate students. The group will reach out to the Navajo Nation to seek the involvement of an undergraduate student.