基于石墨烯纳机电振子的实验研究

发布时间：2018-01-02 03:40

本文关键词：基于石墨烯纳机电振子的实验研究　出处：《中国科学技术大学》2017年博士论文　论文类型：学位论文

【摘要】：石墨烯,自2004年由科学家Geim和Novoselov发现以来,迅速吸引了世界范围内的广泛关注与研究兴趣。石墨烯具有着非凡出众的电学与机械性质,使其成为一种构建纳机电系统的理想材料。本文中,我们针对条带状少层石墨烯纳机电谐振子性能展开研究。本文主要探讨了三个方面的问题:一是实现石墨烯机械振子与量子点两个体系的混合物理结构,研究单电子输运与机械振动模式的强耦合,实现机械模式的直接电学信号转导;二是在串联双机械振子体系中,探索两机械振动模式近邻强耦合以及锁频同步现象;三是实现两个机械振子长程可控调节长程耦合,探讨该体系作为声子网络总线的可能。具体的,本论文有以下主要内容:1.简单介绍石墨烯纳机电系统的基本概念与研究背景,以及本文所涉及到的机械振子、量子点、长程耦合等相关的物理概念。2.介绍了石墨烯机械振子样品制备中的微纳加工设备与工艺。细致的论述了二维材料转移平台与三种转移工艺,并对实验技巧作了详细诠释。简单叙述了多层抗蚀剂悬浮工艺。3.扼要叙述了石墨烯纳米机电谐振子实验测量方法。主要对机械信号电学转导的三种测量方案:混频、耦合微波光子以及直接转导作了详细说明。4.实验上制备出基于石墨烯的量子点与机械振子的混合结构,分别对量子点与机械振子进行了表征,随后探讨了量子点的单电子隧穿与机械振子振动模式的强耦合,实现振动模式信号与量子点输运信号的相互探测。将声子和电子强耦合起来,机械振子成为传输量子信息的声子总线的可能方案。5.对串联双机械振子的两个振动模式进行了研究,实现两机械振动模式的近邻强耦合,并探讨了振动模式的同步现象,通过改变驱动微波的相对相位与功率,观察到两个振动模式基于强耦合的锁频同步现象。6.实验上完成三个机械振子串联耦合结构构造,研究了石墨烯中声子传递过程,通过调节中间机械振子的相对频率实现两侧机械振子的可调共振耦合。本论文的主要创新点有:1.在实验上首次以干法转移的方法获得悬浮细条带石墨烯结构,并在此结构中获得性能优良稳定的石墨烯机械振子。2.在实验上首次实现了石墨烯机械振子与量子点体系的强耦合,在此石墨烯机械振子体系中首次实现直接电学转导输运测量方法。3.通过干法转移的方法,首次实现了石墨烯机械振子之间的强耦合,并首次发现了石墨烯机械振子振动模式的锁频同步现象。4.在实验上首次实现两机械振动模式的可调长程耦合,为构建声子网络或声子总线提供可能。
[Abstract]:Graphene, discovered by scientists Geim and Novoselov in 2004. Graphene has attracted worldwide wide attention and research interest. Graphene has outstanding electrical and mechanical properties, making it an ideal material for building nanoelectromechanical systems. In this paper, we mainly discuss three problems: first, realize the hybrid physical structure of graphene mechanical oscillator and quantum dot system. The strong coupling of single electron transport and mechanical vibration mode is studied to realize direct electrical signal transduction in mechanical mode. The second is to explore the strong coupling between the two mechanical vibration modes and the frequency locking synchronization in the series double mechanical oscillator system. The third is to realize the long-range coupling of two mechanical oscillators, and discuss the possibility that the system can be used as the phonon network bus. The main contents of this thesis are as follows: 1. A brief introduction to the basic concepts and research background of graphene nano-electromechanical system, as well as the mechanical oscillator, quantum dots involved in this paper. Long-range coupling and other related physical concepts .2. introduced the preparation of graphene mechanical vibrator micro-nano processing equipment and technology. The two-dimensional material transfer platform and three transfer processes are discussed in detail. The experimental technique is explained in detail. The suspension technology of multilayer anticorrosive agent .3.The experimental measurement method of graphene nano-electromechanical resonator is briefly described. Three measuring schemes of mechanical signal electrical transduction are introduced. :. Mixing. Coupling microwave photons and direct transduction. 4. The hybrid structures of quantum dots and mechanical oscillators based on graphene have been prepared experimentally and characterized by quantum dots and mechanical oscillators, respectively. Then the strong coupling of single electron tunneling and mechanical oscillator vibration mode of quantum dot is discussed to realize the mutual detection of vibration mode signal and quantum dot transport signal. The phonon and electron are strongly coupled together. The mechanical oscillator becomes the possible scheme of the phonon bus to transmit quantum information. 5. The two vibration modes of the series double mechanical oscillator are studied to realize the strong coupling between the two mechanical vibration modes. The synchronous phenomenon of vibration mode is discussed, and the relative phase and power of driving microwave are changed. Observation of two vibration modes based on strong coupling frequency locking synchronization phenomenon. 6. Three mechanical oscillator series coupling structure was completed experimentally, and the phonon transfer process in graphene was studied. The adjustable resonance coupling of two mechanical oscillators is realized by adjusting the relative frequency of the intermediate mechanical vibrators. The main innovations of this thesis are as follows:. 1. For the first time, the suspended thin strip graphene structure was obtained by dry transfer method. The graphene mechanical oscillator. 2. The strong coupling between the graphene mechanical oscillator and the quantum dot system has been realized for the first time. In this graphene mechanical oscillator system, the measurement method of direct electrical transduction and transport is realized for the first time. 3. The strong coupling between graphene mechanical vibrators is realized for the first time by the method of dry transfer. The frequency locking synchronization phenomenon of graphene mechanical vibrator mode is found for the first time. The adjustable long range coupling of the two mechanical vibration modes is realized for the first time in the experiment, which provides the possibility for the construction of phonon network or phonon bus.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O613.71;TH-39

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