Confined carbyne for optoelectronics and optomechanics

本项目将建立碳纳米管内碳原子的一维线性链碳炔，作为一种新的材料体系，通过光力学相互作用来操纵分子振动，并实现原子尺度上的晶体管。我将利用由碳的原子结构直接产生的碳的两个独特性质。Carbyne是一种peerls材料，存在于金属相中，原子通过双键连接，存在于半导体相中，单键和三键交替连接。Carbyne可以通过掺杂在两相之间切换，这将允许我使用Carbyne作为晶体管通道，通过改变Carbyne的结构相来控制电流。这使得纳米级晶体管在一个原子的沟道横截面上具有绝对更低的尺寸限制，并且与通过掺杂半导体来控制电流的传统晶体管结构完全不同。最近的理论工作表明，通过分子与等离子体纳米结构的强光场的光力学相互作用来操纵分子振动（声子）。这将宏观谐振腔和光学腔之间的光力学相互作用的概念转移到分子尺度，并预测了百万倍的强光力学耦合率。声子可以作为信息载体，从而使光力学中的量子力学效应研究成为可能。然而，目前的实验实现由于等离子体结构产生的强光场驱动分子解体而失败。在这里，我建议通过利用碳炔异常高的拉曼散射截面（分子振动被光非弹性散射的速率）来克服这一限制。这降低了进入光力学相互作用状态所需的场强度，并将允许我在碳炔中制备非热声子种群。声子激光和相关光子的发射作为分子光力学相互作用的两个有趣的结果将被证明。该项目最初旨在探索受限碳炔的声子和激发动力学，以及这些特性如何受到宿主纳米管的影响。我将通过结合尖端增强、温度和波长依赖的拉曼光谱来实现这一目标。在介质电泳沉积中，纳米管作为载流子系统，将受限碳炔引入器件配置并与等离子体结构相连接。电传输测量将验证碳化物晶体管的功能。这个项目建立了局限碳炔作为一种新的材料体系来研究分子光力学，并将使我能够探索新的现象，如光在分子尺度上的频率转换。

This project will establish carbyne, a one-dimensional linear chain of carbon atoms inside a carbon nanotube, as a new material system to manipulate the molecular vibrations through optomechanical interaction, and to realize a transistor on the atomic scale. I will exploit two unique properties of carbyne that arise directly from its atomic structure. Carbyne is a Peierls material which exists in a metallic phase where the atoms are connected by double bonds, and in a semiconducting phase with alternating single and triple bonds. Carbyne can be switched between the two phases by doping, which will allow me to use carbyne as a transistor channel where the current flow is controlled by changing the structural phase of carbyne. This enables a nanoscale transistor at the absolute lower size limit with a channel cross section of one atom, and differs radically from conventional transistor architectures where the current flow is controlled by doping a semiconductor. Recent theoretical works suggest to manipulate molecular vibrations (phonons) through the optomechanical interaction of a molecule with the intense light fields of a plasmonic nanostructure. This transfers the concept of optomechanical interaction between a macroscopic resonator and an optical cavity to the molecular scale, and predicts million-fold stronger optomechanical coupling rates. Phonons can then act as information carriers and allow for the study of quantum-mechanical effects in optomechanics. Current experimental realizations, however, fail due to molecular disintegration driven by the strong light fields generated by the plasmonic structures. Here, I suggest to overcome this limitation by exploiting the exceptionally high Raman scattering cross section of carbyne, the rate at which molecular vibrations are scattering inelastically by light. This reduces the field intensities required to enter the regime of optomechanical interaction and will allow me to prepare non-thermal phonon populations in carbyne. Phonon lasing and the emission of correlated photons as two of the intriguing consequences of molecular optomechanical interaction will be demonstrated.The project initially aims at exploring the phonon and excitation dynamics of confined carbyne and how these properties are influenced by the host nanotubes. I will achieve this by combining tip-enhanced, temperature-, and wavelength dependent Raman spectroscopy. Confined carbyne will be brought into a device configuration and interfaced with plasmonic structures by dielectrophoretic deposition, where the nanotube acts as a carrier system. Electrical transport measurements will verify the functionality of the carbyne transistor. The proposed project establishes confined carbyne as a new material system to study molecular optomechanics and will allow me to explore new phenomena such as the frequency conversion of light on the molecular scale.