GraSP_Graphene Surface Plasmons for Tunable Cavity Quantum Electrodynamics

GraSP项目旨在全面开发石墨烯等离子体纳米结构的前所未有的潜力，以控制和定制光-物质相互作用。石墨烯是一种多功能、宽带、可调节和可调谐的等离子体材料。它将电磁场聚焦到纳米空间区域的能力远远超过贵金属。石墨烯的特征在于对于低于对应于费米能量的阈值的光子能量的吸收损失被严重抑制。通过电选通或化学手段的适当掺杂水平也可以按需转移费米能量。这导致仅通过转动旋钮就可以对石墨烯的光学性质进行宽范围的动态控制。结合达到数百个光学周期的等离子体寿命，这使得基于石墨烯的等离子体纳米结构与原子系统（分子、量子点等）耦合。完美的候选人，以实现纳米级腔量子电动力学系统，将在时间上可调。耦合强度、发射性质、光谱性质、非线性相互作用以及石墨烯光学响应的动态控制使得能够在量子水平上进行信号处理的多种应用。该项目有两个目标。首先，我们希望建立一个理论和数值框架来研究石墨烯纳米结构与相邻原子系统的耦合。这就需要开发技术手段来研究石墨烯纳米结构的光学响应，并研究与原子系统的耦合。其次，我们希望对石墨烯纳米结构控制原子系统动力学和光谱特性的潜力进行全面分析。先前开发的方法构成了彻底理解石墨烯纳米结构提供的控制光-物质相互作用的全部可能性的先决条件。通过这样的分析，我们的目标是为各种应用奠定基础，包括新型的量子逻辑门，多光子非经典光态的产生，或按需激活的原子系统寻址。所有这些设备都将自然地集成在微型芯片上。石墨烯将释放它们的可调性，这是GraSP中讨论的应用的一个至关重要的属性，然而传统的金属等离子体很难实现。该项目将在卡尔斯鲁厄理工学院（KIT）和托伦的尼古拉斯哥白尼大学（NCU）平行执行。这两个合作伙伴为这个项目带来了互补的专业知识。来自C. Rockstuhl（KIT）专注于研究石墨烯纳米结构的等离子体特性。从K组。Slowik（NCU）研究量子动力学。要实现这些目标，只有在目前的合作中才有可能，需要双方共同努力。

The GraSP project aims at a comprehensive exploitation of the unprecedented potential of graphene-based plasmonic nanostructures to control and to tailor light-matter interactions. Graphene is a versatile, broadband, adjustable, and tunable plasmonic material. Its ability to focus electromagnetic fields into nanometric regions of space is well beyond that of noble metals. Graphene is characterized by heavily suppressed absorption losses for photon energies below a threshold corresponding to the Fermi energy. A suitable level of doping via electric gating or chemical means can also shift the Fermi energy on-demand. This results in a wide-range dynamic control of the optical properties of graphene by merely turning a knob. Combined with the plasmonic lifetimes reaching hundreds of optical cycles, this renders graphene-based plasmonic nanostructures coupled to atomic systems (molecules, quantum dots, etc.) perfect candidates to implement nanoscale cavity-quantum-electrodynamics systems that would be tunable in time. Coupling strengths, emission properties, spectral properties, nonlinear interactions in addition to a dynamic control of graphene optical response enables multiple applications for signal processing at the quantum level. The objectives of the project are twofold. At first, we wish to establish the theoretical and nume-rical framework to investigate the coupling of graphene nanostructures to adjacent atomic systems. This requires the development of technical means to study the optical response of graphene nanostructures and to study the coupling to atomic systems. At second, we wish to perform a comprehensive analysis of the potential of graphene nanostructures to control the dynamics and spectral properties of atomic systems. The previously developed methodology constitutes here a prerequisite to thoroughly understand the full range of possibilities to control light-matter interaction offered by graphene nanostructures. With such analysis we aim to lay down the ground for diverse applications, including new types of quantum logic gates, generation of multiphoton nonclassical states of light, or atomic systems addressing activated on demand. All these devices would be naturally integrated on miniaturized chips. Graphene would unlock their tunability, a property of crucial importance for applications discussed within GraSP, however hardly accessible with traditional metal plasmonics.The project will be executed in parallel at the Karlsruhe Institute of Technology (KIT) and at the University of Nicolaus Copernicus (NCU) in Torun. The two partners bring into this project complementary expertise. The group from C. Rockstuhl (KIT) concentrates on studying the plasmonic properties of graphene nanostructures. The group from K. Slowik (NCU) studies the quantum dynamics. To achieve the objectives is only possible in the present collaboration and requires mutual efforts.