学术预告 | 广东省磁电物性分析与器件重点实验室学术讲座（第五十三期）：过渡金属硫化物中激子的多体和拓扑相

报告人:朱起忠 副研究员（华南师范大学物理学院）

题   目：过渡金属硫化物中激子的多体和拓扑相

地   点：中山大学南校园550栋二楼报告厅

时   间：2025年4月29日（星期二）上午10:10

主持人：侯玉升 副教授

报告摘要：

In this talk, I will discuss the intriguing many-body phases of valley excitons in transition metal dichalcogenides (TMDs) and their heterostructures. I will begin with a brief overview of unconventional exciton superfluids and topological phases, including quantum anomalous Hall and quantum spin Hall insulators, predicted in monolayer and heterobilayer TMDs, respectively. I will then focus on our recent work on exciton topological bands and many-body phases in twisted TMD heterotrilayers. I will demonstrate that twisted TMD heterotrilayers—specifically, WX2/MX2/WX2 with layer symmetry—provide a realistic platform for realizing topological exciton bands and interesting many-body excitonic phases by simply tuning the twist angle. Interlayer excitons with opposite dipoles become hybridized through coupling between the two outer layers, leading to topological moiré exciton bands. By developing a three-orbital tight-binding model, we mapped the many-body phase diagram for interacting dipolar and quadrupolar excitons at various twist angles and exciton densities. Our work opens up new possibilities for realizing exciton topological flat bands and exciton fractional topological phases in twisted TMD systems.

报告人简介：

朱起忠，华南师范大学物理学院副研究员。2010年本科毕业于山东大学光信息专业，2015年博士毕业于北京大学量子材料中心，之后在香港大学物理系做博士后，2019年7月加入华南师范大学。主要研究方向为冷原子和二维材料中的多体和拓扑相，在Science Advances, Physical Review Letters, Nano Letters, Physical Review A/B等期刊发表论文20余篇。