Electrically controlling correlated phases in semiconductor moiré superlattices

讲演择要：
Semiconductor moiré superlattices formed by stacking layered transition metal dichalcogenides have attracted significant attention due to their unique properties and potential applications. These moiré systems have demonstrated various phenomena, including abundant correlated insulating states, anomalous quantum Hall effect, excitonic insulator, and ferromagnetism, which enable them promising in various applications, such as quantum simulator.

In this talk, I will first discuss our work on electrically controlling correlated phases in WSe2/MoS2 moiré superlattices. By utilizing an interlayer exciton optical sensor, we investigated the correlated insulating states in the WSe2/MoS2 moiré superlattice and found a strong correlation between the interlayer exciton photoluminescence intensity and lifetime. Importantly, we achieved layer-dependent correlated phase control, including single-layer, layer-selective, excitonic-insulator, and layer-hybridized phases, through the application of electric fields and doping. Then, I will talk about the giant optical nonlinearity of interlayer excitons in WSe2/MoS2 Moiré superlattices, we demonstrated that the coherence of moiré interlayer excitons can be enhanced through boson excitonic correlation and effects of Fermions correlated insulating states. Our work represents a significant step towards the application of semiconductor moiré materials in the fields such as quantum simulators and quantum information processors.

讲演人简介：
谭青海博士，中科年夜微电子学院，特任传授，2018年博士结业于中国迷信院半导体研究所，导师为谭平恒研究员、张俊研究员；2019年-2023年以博后身份正在新加坡南洋理工年夜学开展研究事情，互助导师为高炜博传授；2023年-2024年正在新加坡科技研究局任职高级研究员，2024年3月参加中科年夜微电子学院。今朝首要研究乐趣包含半导体莫尔异质结中别致量子态的摸索与调控、激子能源学研究与调控、新型量子传感器和红外光电探测器等。