CAREER: Warm Quantum Materials: Harnessing Exotic Quantum Properties at High Temperatures

非技术摘要：超导性是凝聚态物理学中最深刻的现象之一，具有完全不存在电阻的性质。在室温或接近室温的环境压力下实现超导状态是开创性的。压力已被证明是制造新材料（如超导体）中最通用的调谐参数。富氢材料，模仿难以捉摸的固体金属相的氢，可以在低得多的压力下金属化，促进高Tc超导在低得多的压力。该项目的主要目标是在环境压力下合成新型富氢，室温或高于室温的超导材料，用于实际应用，例如先进的电网，新的运输，医学成像和扫描技术，如MRI和心磁图，以及更快，更高效的数字逻辑和存储器技术。该项目还为高压实验提供了重要的研究基础设施，能够解决材料科学中的各种问题。首席研究员将创建教育媒体，以支持世界各地的教学和学生学习。获得直接支持的群体包括研究生获得大型用户设施和学习必要的研究技能;当地高中教师与主要研究者合作，直接应用课堂概念;为第一代大学，低收入和代表性不足的少数民族学生提供研究机会;并改善和建立聋人社区可用的资源。技术摘要：量子材料的性质对压力等外部刺激非常敏感，这会产生奇异的，往往是前所未有的性质。在一类新的致密富氢材料超导体中发现的高Tc超导性，使人们对室温或温超导性的长期探索重新焕发了活力。超光速依赖于氢分子的离解作用，氢分子提供了费米能级附近能量状态所需的额外电子。然而，到目前为止，理论和实验研究主要集中在二元超星系。该项目中设想的努力代表了一个自然和及时的研究方向，以发现和理解新型三元和四元超导体的结构，化学键合和稳定性，其Tc相当于或高于室温，并通过成分调整，降低转变压力，同时保持超导性能。此外，为了理解这些热超导体的量子性质，在高压实验中主要需要绝对温度测量。为了满足这一需求，氮空位中心提供了一种新的方法，可以将压缩材料的原位温度测量确定到Mbar范围内，这将是革命性的。仔细的热测量可能会增加测量超导超导体热容的能力，这是一种上级超导测试。这项工作将使研究团队能够更广泛地了解超导性，包括稳定性，因此，为变革性技术设计一类新的温暖量子材料。该奖项反映了NSF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:Superconductivity is one of the most profound phenomena in condensed matter physics and has the property of complete absence of electrical resistance. Achieving a state of superconductivity at room temperature or near room temperature at ambient pressure is groundbreaking. Pressure has been proven to be the most versatile tuning parameter in making novel materials, such as superconductors. Hydrogen-rich materials, mimicking the elusive solid metallic phase of hydrogen, can be metalized at much lower pressures, promoting high-Tc superconductivity at much lower pressures. The primary goal of this project is to synthesize novel hydrogen rich, room temperature or above room temperature superconducting materials at ambient pressure for practical applications, such as advanced power grids, new transportation, medical imaging, and scanning techniques such as MRI and magnetocardiography, and faster, more efficient electronics for digital logic and memory device technology. The project also provides an important research infrastructure for high pressure experiments with capabilities of addressing a diverse set of problems in materials science. The principal investigator will create educational media to support teaching and student learning all over the world. Groups receiving direct support include graduate students gaining access to large user facilities and learning necessary research skills; local high school teachers collaborating with the principal investigator on direct application of classroom concepts; research opportunities for first-generation college, low-income, and underrepresented minority students; and improving and building upon resources available to the Deaf community. Technical Abstract:The properties of quantum materials are anomalously sensitive to external stimuli such as pressure, which give rise to exotic and often unprecedented properties. The long-standing quest for room-temperature or warm superconductivity has been reinvigorated by the discovery of high Tc superconductivity in a new class of dense, hydrogen-rich materials—superhydrides. The superhydrides rely on the role of the dissociation of the hydrogen molecules, which provide the extra electrons needed in energy states near the Fermi level. However, thus far, theoretical and experimental studies are mainly focused on binary superhydrides. The efforts envisioned in this project represent a natural and timely research direction to discover and understand structure, chemical bonding, and stability of novel ternary and quaternary superconductors with Tc comparable to or higher than room temperature and via compositional tuning, lowering the transition pressure while preserving the superconducting properties. Furthermore, in order to understand the quantum nature of these hot superconductors, there is a major need for absolute temperature measurements in high pressure experiments. To remedy this need, Nitrogen vacancy centers provide a new way to potentially determine the in-situ temperature measurement for compressed materials into the Mbar range, which would be revolutionary. Careful thermal measurements would likely increase the ability to measure the heat capacity on superconducting superhydrides, which is a superior test for superconductivity. The work will allow the research team to obtain insight into superconductivity more broadly including the stabilities, and as such, to the design of a new class of warm quantum materials for transformative technologies.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.