过渡金属硫化物TaS2的量子输运特性及其调控研究

Transition-metal dichalcogenides (TMDCs) have attracted great attention in recent years, as they exhibit numerous intriguing physical properties originating from strong interactions between multiple freedom of degrees, such as charge, spin, orbit and lattice. In this project, benefiting from diversely state-of-the-art techniques in the High Magnetic Field Laboratory of the Chinese Academy of Science, we propose to investigate the physical properties of TaS2 system. By utilizing quasi-one-dimensional quantum confinement, tuning the twist angles between the TaS2 heterostructures and introducing the superconducting proximity effect (SPE), we aim to experimentally study the magnetotransport properties and to explore the possible new quantum states in TaS2, which have not been envisioned. The fulfillment of this project will greatly advance our understanding of the interactions of different freedom of degrees, and the successful outcome of this project will reveal the possible mechanisms of the formation of charge density wave phases and the competition between charge density wave phases and superconducting phases in TaS2. In addition, we attempt to explore the manipulation of physical properties of TaS2 in a periodic and controllable way, which will pave the way for future applications of TaS2 system in electronic devices.

过渡金属硫化物由于电荷、自旋、轨道以及晶格等量子序之间的强关联耦合作用，表现出新奇的物理特性，引起广泛的关注。本项目以过渡金属硫化物TaS2作为研究对象，依托中国科学院强磁场科学中心的低温、强磁场环境下的多种表征手段系统研究一维量子限域、层间扭曲角度以及超导近邻效应对TaS2量子输运特性的调控作用，探索新奇量子态。我们希望通过本项目的开展，能够深入理解TaS2体系中各量子序之间的关联相互作用，揭示电荷密度波相的形成以及电荷密度波相与超导相的竞争机制。在此基础上，进一步探索周期性可控调制TaS2体系中量子态的方法，为基于TaS2的新型电子器件设计与开发提供科学基础。

在本项目的支持下，我们围绕调控低维量子材料磁电输运物性和揭示各量子序之间的关联相互作用两个基本科学问题开展了系统的研究。取得的主要创新成果包括：1)构筑了基于s-波超导的异质复合结构(2H-TaS2/NbSe2)，揭示了界面超导近邻效应对超导特性的增强作用；2)构筑了不同扭曲角度的2H-TaS2同质结，实现了对2H-TaS2的电荷密度波和超导特性的调控，并在特定扭曲角度发现了低磁场的电阻振荡；3)通过非磁性硫族元素取代以及外加磁场，实现了二维范德华层状反铁磁材料的低温磁性的调控；4)发现了二维滑移铁电材料中的铁电序与体光伏效应的非协同变化关系；5)实验发现了一维电荷密度波TiS3体系的电阻回滞特性，揭示了维度对电荷密度波的调制作用。在项目执行期间，共计正式发表SCI论文5篇，已接收发表SCI论文2篇，包括1篇Phys. Rev. B，3篇Appl. Phys. Lett.，1篇npj Comput. Mater.等。