Transition-metal dichalcogenide heterostructures as a robust, tunable platform for studying exciton-exciton interactions

本项目的目标是建立过渡金属二硫属化物异质结构（TMDC-HS）作为一个强大的，可调的平台，用于研究层间激子及其相互作用。由于它们的玻色子性质，激子具有作为温度和密度的函数的丰富的相图。层间激子在TMDC-HS提供了几个优势，更成熟的GaAs基异质结，包括显着更大的激子结合能，新颖的自由度和设计参数，如相邻单层的相对取向。然而，它们也带来了挑战，这是由于它们对环境的敏感性，导致明显的不均匀加宽，比高质量GaAs异质结构大得多。我们建议优化制造TMDC-HS使用封装在其他二维材料（如六方氮化硼），并集成纳米结构的电极，定义静电陷阱激子约束。我们将利用各种光谱技术来表征这些新的结构，并研究层间激子在高密度和低温下的动力学。

The goal of this project is to establish transition-metal dichalcogenide heterostructures (TMDC-HS) as a robust, tunable platform for studying interlayer excitons and their interactions. Due to their bosonic nature, excitons have a rich phase diagram as a function of temperature and density. Interlayer excitons in TMDC-HS offer several advantages over more established, GaAs-based heterostructures, including significantly larger exciton binding energies, the novel valley degree of freedom and design parameters such as the relative orientation of adjacent monolayers. However, they also present challenges which stem from their sensitivity to the environment, leading to pronounced inhomogeneous broadening that is much larger than in high-quality GaAs heterostructures. We propose to optimize the fabrication of TMDC-HS using encapsulation in other two-dimensional materials (e.g. hexagonal Boron Nitride), and to integrate nanostructured electrodes which define electrostatic traps for exciton confinement. We shall utilize various optical spectroscopy techniques to characterize these novel structures and to investigate the dynamics of interlayer excitons in the regime of high densities and low temperatures.