准二维层状材料RTe3体系的高压磁输运性质研究

稀土金属三碲化物RTe3(R=La-Nd, Sm以及Gd-Tm)的晶体结构具有典型的准二维特性，在压力下表现出包含电荷密度波、反铁磁相、超导相的复杂相图。系统地研究RTe3体系三种量子态之间的相互作用，对揭示其作用机理，尤其是对研究铜氧化合物高温超导体等具有类似相图的准二维材料，将会有着重要的科学意义。本项目旨在通过高压作为调控手段，系统地研究RTe3材料的磁输运性质在压力下的演化情况。随着CDW相逐渐被压力抑制，研究超导相随压力的变化，判断CDW和超导之间是否存在竞争行为；探索准粒子有效质量是否存在发散状增加等反常行为，寻找CDW型量子临界点存在的证据；通过对比加压后的磁输运性质变化，研究反铁磁序在反常SdH量子震荡的作用。最后，对比样品厚度变薄前后的磁输运性质，判断厚度在少层样品反常线性磁阻等现象中的作用。本项目的完成将为理解准二维材料中的复杂相图提供一定的实验依据。

Rare-earth tritelluride compounds RTe3 (R=La-Nd, Sm and Gd-Tm), with the quasi-two-dimensional layered crystal structure, exhibit a complex phase diagram with charge density wave (CDW), antiferromagnetic order and superconductivity under pressure. Systematic investigation of the interplay between these three collective orders in RTe3 may shed new light of the interacting mechanism of multiple degrees of freedom, especially in quasi-two-dimensional layered materials with similar phase diagram such as the famous high Tc superconductors cuprate. In this proposal, we aim to measure the magnetotransport properties of RTe3 with pressure as the tuning parameter. As the CDW order suppressed gradually by pressure, the evolution of superconducting phase would reveal useful information about the competition with CDW order, at the same time, anomalies including diverging effective mass would be expected if quantum critical point with CDW type would exist. In addition, we will also investigate the role of antiferromagnetic order in the anomalous Shubnikov-de Hass quantum oscillation by comparing with magnetotransport properties at ambient pressure. Finally, the thickness dependence of the magnetotransport properties will be studied to find how the thickness changes the electronic properties of these materials. This project will be meaningful for a better understanding of the quasi-2D materials with similar phase diagram.