State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
Center of Materials Science and Optoelectronics Engineering and CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Nano. 2023 Mar 28;17(6):5956-5962. doi: 10.1021/acsnano.3c00180. Epub 2023 Mar 10.
Graphene is an ideal platform to study the coherence of quantum interference pathways by tuning doping or laser excitation energy. The latter produces a Raman excitation profile that provides direct insight into the lifetimes of intermediate electronic excitations and, therefore, on quantum interference, which has so far remained elusive. Here, we control the Raman scattering pathways by tuning the laser excitation energy in graphene doped up to 1.05 eV. The Raman excitation profile of the G mode indicates its position and full width at half-maximum are linearly dependent on doping. Doping-enhanced electron-electron interactions dominate the lifetimes of Raman scattering pathways and reduce Raman interference. This will provide guidance for engineering quantum pathways for doped graphene, nanotubes, and topological insulators.
石墨烯是一个理想的平台，可以通过调节掺杂或激光激发能量来研究量子干涉途径的相干性。后者产生的喇曼激发谱提供了对中间电子激发态寿命的直接了解，因此，对量子干涉的研究一直难以捉摸。在这里，我们通过调节激光激发能量来控制掺杂高达 1.05 电子伏特的石墨烯中的喇曼散射途径。G 模式的喇曼激发谱表明其位置和半最大值全宽与掺杂呈线性关系。掺杂增强的电子-电子相互作用主导喇曼散射途径的寿命并减少喇曼干涉。这将为工程化掺杂石墨烯、碳纳米管和拓扑绝缘体的量子途径提供指导。
