[超导国家重点实验室学术报告] Superconducting materials hosting nontrivial topology

Topological superconductors have attracted tremendous interest for hosting Majorana bound states on their boundaries, which are potential in realizing quantum computations. One promising approach to engineer topological superconductors is to discovery superconductors with nontrivial topology in their electronic band structure. In this talk, I will introduce our recent work on exploration of such materials. Specifically, I will first talk about our high-pressure measurement on the topological nodal-line semimetal SrAs3, which induces a Lifshitz transition below 1 GPa and then superconductivity at 20.6 GPa associated with a structural phase transition. The new cubic SrAs3 phase is found to host not only superconductivity but also a topological crystalline insulator state. I then will introduce our recent high magnetic field magnetotransport measurement on the layered superconductor TaSe3, which reveals the existence of a strong topological insulator state.

[超导国家重点实验室学术报告] 从组合材料学到材料基因组学

结合20多年从事组合材料学的工作经验，从并行合成、高通量表征两个方面阐述组合材料学的思想精髓，并通过两个具体的材料研究，展现组合方法的优越性。同时，也和听众一起回顾从组合材料学到材料基因组学的螺旋发展历程，探讨材料基因组计划孕育的机遇和挑战。

[超导国家重点实验室学术报告] 关联氧化物纳米电子学

关联氧化物纳米电子学结合了关联氧化物物理学与半导体纳米电子学两个领域，为新近发展起来的交叉领域。在这个报告中，我会首先介绍关联氧化物纳米电子学的背景，然后用几个例子来阐述氧化物中的关联性与半导体器件相辅相成的研究特性以及可能应用。在第一个例子中，我会介绍我们在铝酸镧/钛酸锶（LAO/STO）界面上制备超导单电子晶体管，并观测到了超导外电子配对的实验证据[1]，验证了一个悬浮半个世纪的理论。从而阐明纳米器件为研究电子关联性提供了重要工具。在第二个例子中，我会着重介绍氧化物电子/电子对波导中的量子输运，阐明电子关联性丰富了纳米器件的特性[2]。最后我会介绍最近两年来在这个领域中我们取得的一些新进展，包括可调的电子-电子相互作用[2], 氧化物界面量子振荡的一维根源性[3]与氧化物纳米线的一维超导性[4]以及可能的应用。

[超导国家重点实验室学术报告]三角晶格稀土氧族化合物AReCh2中自旋激发的研究进展

阻挫磁性是当今凝聚态物理研究的重要内容。虽已经历长期探索，在自旋阻挫材料中寻找量子自旋液体仍然是一个富有挑战的课题。在许多已知的量子自旋液体候选材料中，磁性杂质、结构缺陷、无序等的存在都会影响人们对其磁基态的判断，从而降低其量子自旋液体基态的可信度。因而，寻找不存在结构缺陷、无序的阻挫磁性材料是实现量子自旋液体的重要前提。2018年出现的具有铜铁矿结构的三角晶格稀土氧族化合物AReCh2 (A为碱金属，Re为稀土元素，Ch为氧族元素)中被证明不易存在结构缺陷和无序，而且很多AReCh2材料在实验中都没有形成磁有序，因此被认为是实现量子自旋液体态的理想材料体系。随后的非弹性中子散射也相继在NaYbO2，NaYbSe2等材料中观测到了连续的自旋激发，被认为是分数化的自旋子激发，为量子自旋液体态的存在提供了重要证据。

[超导国家重点实验室学术报告]Electronic state control in layered quantum materials

The multifunctional behaviors of quantum materials are driven by the intricate interplay between charge, orbital and spin degrees of freedom. Advances in modern field-effect devices allow for unprecedented control of these degrees of freedom, revealing a plethora of exotic physical phenomena such as superconductivity and long-range magnetic order. In this talk, I will provide an overview of our recent progress in controlling the emerging physical phenomena in layered quantum devices and how they offer new insights to the underlying physics. First, I will discuss the observation of a spontaneous anomalous Hall effect, a trademark of time-reversal symmetry breaking, in a doped layered polar semiconductor. Notably, the magnitude of anomalous Hall conductivity can be enhanced by tuning the carrier density, which sheds new light on the interplay of magnetic and ferroelectric-like responses [1]. Next, I will present recent results on the electric field control at the interfaces of ionic gated tellurium thin flake devices, demonstrating a fourfold increase in the Rashba spin-orbit coupling coefficient.

超导实验室学术报告1

超导实验室学术报告
超导实验室学术报告