新奇超导体的极低温性质及压力、栅压调控研究

新奇超导体的研究一直是凝聚态物理的前沿，如重费米子超导体、铜基和铁基高温超导体、近期的镍基超导体等。对超导体的物性进行测量和调控，阐明超导机理，不仅在科学上可以促进凝聚态物理领域的发展，而且在实际中对能源和信息方面的应用也具有重要意义。本项目将对新奇超导体的极低温性质进行测量，并开展压力和栅压调控研究，重点研究最新发现的具有阻挫Kagome晶格的钒基超导体。具体将开展以下几个方面的研究：（1）对钒基超导体（K,Rb,Cs)V3Sb5及相关材料进行极低温电、热输运性质测量，研究其超导能隙结构及拓扑电子态行为；（2）对钒基超导体及拓扑材料开展高压研究，绘出超导转变温度-压力相图；（3）对钒基超导体薄层样品研究维度对其超导转变和电荷密度波转变的影响，并开展栅压调控研究，对其它准二维超导体如铁基超导体也开展维度及栅压调控研究。我们期望在新奇超导体的超导机理和物态调控方面取得突破性成果。

The study of novel superconductors is always the frontier of condensed matter physics, for examples, the heavy-fermion superconductors, Cu-based and Fe-based high-Tc superconductors, the recent Ni-based superconductors. Studying and manipulating the physical properties of superconductors, clarifying their superconducting mechanism, will not only advence the field of condensed matter physics, but also have great impact on the energy and information applications. This project will measure the ultralow-temperature properties of novel superconductors, and apply pressure and gate voltage to manipulate them. We will mainly focus on the newly discovered V-based superconductors, which have frustrated Kagome lattice. Our studies will include: (1) For the V-based superconductors (K, Rb, Cs)V3Sb5 and related materials, we will measure their ultralow-temperature elctrical and thermal transport properties, to investigate their superconducting gap structure and topological electronic state. (2) We will apply high pressure on V-based superconductors and other topological materials, to map out their Tc vs pressure phase diagram. (3) We will study the effect of dimensionality on the Tc and CDW transition of thin flakes of V-based superconductors, and manipulate them by gating. We will also study the dimensionality and gating effects on other quasi-two-dimensional superconductors such as Fe-based superconductors. We expect to get breakthroughs on the superconducting mechanism and physical state manipulation of novel superconductors.