CAREER: Discovering and Understanding Layered Nickelate Superconductors

非技术总结该奖项支持一项综合性的研究、推广和教育工作，以促进对超导材料的基本理解。超导性是物质的一种量子状态，在这种状态下，电子在材料中移动时没有阻力，也就是说，不会因为热而损失任何能量。超导材料对不同的技术至关重要：从磁共振成像机到高能物理加速器，再到磁悬浮列车。然而，它们的有效性往往受到超导性通常出现的令人望而却步的低温的限制。提高这种转变温度和发现新的超导体一直受到限制，因为对于是什么导致某些类别的材料具有超导电性缺乏共识。其中一类以铜氧化物为代表，它在20世纪80年代的发现对物理学产生了深远的影响，因为它们可以在比当时已知的任何物质更高的温度下超导。该项目将使用先进的计算和理论方法来研究镍氧化物-基于元素周期表中镍与铜的接近程度而有望成为超导材料的候选材料。该项目的目标是发现一种新的镍基超导体家族，同时为高温超导的起源提供见解。该团队将开发适用于超导材料的计算方法，并对电子进行模拟，以确定镍和铜氧化物物理之间的区别和相似之处。第一个镍氧化物超导体家族的发现将开辟新的场所，并建立产生超导的相关参数。这是提高超导产生的温度和提供创造新型超导材料的途径所必需的成分。研究活动与教育和推广计划相结合，将超导和物理计算建模带给凤凰城的学生和普通公众。该计划的重点是通过为拉美裔占多数的社区的高中女生举办外展日，以及通过为来自低收入地区的学生举办一系列计算机化的暑期研讨会，来指导服务不足地区的高中生。这些活动的更广泛影响将是年轻有才华的学生及早接触研究，他们通常看不到他们所在社区的科学职业道路。PI还将为开放参观活动开发演示，以教育和参与普通公众对超导材料的了解。最后，该奖项将通过招募和建议本科生和研究生参与凝聚态物理和材料研究，为形成未来的科技队伍做出贡献。该奖项支持一项综合性的研究、推广和教育工作，以促进对超导材料的基本理解。在超导发现一个多世纪后，超导仍然是凝聚态物理研究中最活跃的领域之一。自20世纪80年代末开始对铜酸盐进行密集勘探后，2006年发现的铁基超导体重振了该领域的活力。然而，查明高温超导的机制，确定高温超导材料的特性为何如此特殊，是有待回答的根本问题。在解决这些问题的多种方法中，一直在寻找铜酸盐模拟材料。在这种情况下，目标是镍酸盐是一个明显的战略，因为镍和铜在元素周期表中紧挨着。这个项目将开发理论和计算方法来研究层状镍氧化物材料的超导电性。这项拟议研究的明确目标是发现并建立第一类镍酸盐超导体的理论基础，同时以微观的方式研究它们的行为。理论方法将从快速密度泛函理论到计算密集的准粒子自洽GW+动力学平均场理论计算。通过这种方法，该团队将确定层状镍酸盐相图的复杂性，其中的竞争相与超导电性之间的关系，并最终为高温超导的性质和起源提供新的见解。与超导铜酸盐的系统比较将为产生高温超导的相关参数奠定基础，并建立创造新型超导材料的途径。与研究工作相结合，PI将建立一个教育和推广计划，通过i)为来自低收入地区的高中生举办计算暑期研讨会，ii)在以拉丁裔为主的社区为高中女孩举办外联日，以及iii)以超导为中心的开放参观活动，将超导和计算物理建模带给学生和公众。这些外展和教育努力将使亚利桑那州立大学服务的社区直接受益，因为它让广泛的人群接触科学，并通过影响通常认为他们的社区没有科学职业道路的年轻一代。最后，通过招募本科生和研究生参与凝聚态物理研究，该奖项将有助于形成未来的科技队伍。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NONTECHNICAL SUMMARYThis award supports an integrated research, outreach, and educational effort to advance the fundamental understanding of superconducting materials. Superconductivity is a quantum state of matter whereby electrons move through a material without resistance, namely, without losing any energy to heat. Superconducting materials are of paramount importance to different technologies: from magnetic resonance imaging machines to accelerators for high-energy physics, and magnetic levitating trains. However, their usefulness is often restricted by the prohibitively low temperatures at which superconductivity usually emerges. Increasing this transition temperature and discovering new superconductors has been limited by the lack of consensus as to what causes superconductivity in some classes of materials. One of these classes is represented by copper oxides whose discovery in the 1980s had a profound influence on physics as they could superconduct at a higher temperature than any material known at the time. This project will use advanced computational and theoretical methods to investigate nickel oxides - promising candidate materials for superconductivity based on the proximity of nickel to copper in the periodic table. The goal of the project is to discover a new family of nickel-based superconductors while providing insights into the origin of high-temperature superconductivity. The team will develop computational approaches suited for superconducting materials and perform simulations of electrons to establish the differences and similarities between the physics of nickel and copper oxides. The discovery of the first family of nickel oxide-based superconductors will open new venues and establish the relevant parameters that give rise to superconductivity. This is a necessary ingredient to enhance the temperatures at which superconductivity emerges and to provide routes to create novel superconducting materials. The research activities are integrated with an educational and outreach program to bring superconductivity and computational modeling in physics to students and to the general public in metro Phoenix. The program has an emphasis on mentoring high-school students from underserved areas via an outreach day for high-school girls in majority-Latino neighborhoods, and through a series of computational summer workshops for students from low-income areas. The broader impact of these activities will be early exposure to research for young talented students who generally do not see science career paths represented in their communities. The PI will also develop demos for open house events to educate and engage the general public on superconducting materials. Finally, this award will contribute to forming tomorrow's scientific and technological workforce by recruiting and advising undergraduate and graduate students to participate in condensed matter physics and materials research. TECHNICAL SUMMARY This award supports an integrated research, outreach, and educational effort to advance the fundamental understanding of superconducting materials. More than a century after its discovery, superconductivity remains one of the most active areas of condensed matter physics research. The discovery of iron-based superconductors in 2006 reinvigorated the field after an intensive exploration of cuprates from the late 1980s. However, pinpointing the mechanism of high-temperature superconductivity and determining why the characteristics of high-temperature superconducting materials are so special are fundamental questions yet to be answered. Among the multiple approaches to addressing these questions has been the search for cuprate analog materials. In this context, targeting nickelates is an obvious strategy since nickel and copper are next to each other in the periodic table. This project will develop theoretical and computational approaches to investigate superconductivity in layered nickel oxide materials. The explicit goal of the proposed research is to discover and establish the theoretical foundations of the first family of nickelate superconductors while addressing their behavior in a microscopic way. The theory approach will run the gamut from fast density functional theory to computationally intensive quasiparticle-self consistent GW+dynamical mean-field theory calculations. With this methodology, the team will determine the complexity of the layered nickelate phase diagram, the relationship between competing phases therein and superconductivity, and ultimately provide new insights into the nature and origin of high temperature superconductivity. The systematic comparison with superconducting cuprates will lay the foundation of the relevant parameters that give rise to high-temperature superconductivity and establish routes to create novel superconducting materials. Integrated with the research efforts, the PI will establish an educational and outreach program to bring superconductivity and computational modeling in physics to students and to the general public in metro Phoenix through i) a computational summer workshop for high school students from low-income areas, ii) an outreach day for high school girls in majority-Latino neighborhoods, and iii) open house events centered around superconductivity. These outreach and educational efforts will directly benefit the community Arizona State University serves by exposing a wide cross-section of people to science and by influencing younger generations that generally do not see science career paths represented in their communities. Finally, this award will contribute to forming tomorrow's scientific and technological workforce by recruiting undergraduate and graduate students to participate in condensed matter physics research.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.