CAREER: Probing Nematic Superconductivity in Topological Semimetals

非技术摘要：理解和控制新型量子材料的物理性质是未来技术的关键。例如，最近的理论研究预测，一种被称为拓扑超导体的新型量子材料可能在量子计算中有用。尽管人们为发现这种超导体付出了巨大的努力，但迄今为止只发现了少数几种有希望的候选材料，而且人们对它们的性质知之甚少。本项目的目标是通过先进的实验技术阐明新型量子材料中超导性与拓扑之间的联系，从而确定实现拓扑超导性的关键因素。项目成果将影响基础科学研究，也将影响未来在能源、信息和电子技术方面的应用。与研究相结合，该项目旨在通过美国物理学会资助的桥梁项目以及瓦伦西亚-中佛罗里达大学物理研究交流项目，提高学生，特别是代表性不足的学生在STEM领域的质量，参与度和保留率。教育材料将提供给学生、研究人员和公众。技术文摘：拓扑和对称破缺是物质新量子相的关键组成部分。结合打破U(1)规范对称的超导性，拓扑秩序可以容纳在系统边界产生的马约拉纳费米子。然而，利用马约拉纳费米子潜力的一个主要瓶颈是缺乏拓扑超导的原型平台。最近的实验和理论研究表明，拓扑结构与涉及电子向列性的独特超导间隙结构有关。本项目研究超导拓扑半金属中向列超导与拓扑的相互关系，旨在找出利用马约拉纳费米子实现拓扑超导的关键因素。为了实现这一目标，本文提出的具体研究目标是：(1)通过化学取代控制各种物理参数来设计拓扑半金属中拓扑与向列性之间的相互作用；(2)通过磁场角分辨热输运和热容测量来识别拓扑半金属中的向列超导性；(3)观察拓扑半金属超导态中的分形激发。教育与研究紧密结合的要素包括材料研究的高级本科综合实验室-讲座课程的教育内容，为未来技术所需的材料研究培养强大的STEM劳动力，以及提高学生，特别是代表性不足的学生对STEM学科的参与和保留。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical abstract: Understanding and controlling the physical properties of novel quantum materials is key to future technologies. For example, recent theoretical studies have predicted that a new type of quantum materials called topological superconductors may be useful in quantum computing. Despite intensive efforts to discover such superconductors, only a handful of promising candidates have been found to date, and little is known about their properties. The goal of this project is to identify the key ingredients to realize topological superconductivity, by elucidating the connection between superconductivity and topology in novel quantum materials through advanced experimental techniques. The project outcomes will impact fundamental scientific research, but also future applications in energy, information and electronic technologies. Integrated with research, this project aims to increase quality, participation, and retention of students, particularly underrepresented students, in STEM fields through the American Physical Society-funded Bridge Program as well as Valencia-University of Central Florida Physics Research Exchange Program. Education materials will be made available to students, researchers, and the general public.Technical abstract: Topology and symmetry breaking are key ingredients of novel quantum phases of matter. Combined with superconductivity that breaks the U(1) gauge symmetry, topological order can host Majorana fermions arising at the boundaries of systems. However, a major bottleneck to employ the potential of Majorana fermions is a lack of prototypical platforms for topological superconductivity. Recent experimental and theoretical studies suggest that topology is linked to the unique superconducting gap structures involving electronic nematicity. This project investigates the interrelation between nematic superconductivity and topology in superconducting topological semimetals, aiming at identifying key ingredients to realize topological superconductivity with Majorana fermions. To achieve this aim, the specific research objectives proposed here are: (1) engineer the interplay between topology and nematicity in topological semimetals with controlling various physical parameters by chemical substitutions, (2) identify nematic superconductivity in topological semimetals via magnetic field angle-resolved thermal transport and heat capacity measurements, and (3) observe fractionalized excitations in the superconducting state of topological semimetals. The elements of close integration of education with research include the educational content of upper-level undergraduate integrated lab-lecture course for materials research, training of a strong STEM workforce for materials research that is needed for future technologies, and enhanced participation and retention of students, in particular underrepresented students, in STEM disciplines.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.