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

职业：温量子材料：在高温下利用奇异的量子特性

• 批准号: 2046796
• 负责人: Ranga Dias
• 金额: $ 79.44万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2046796&HistoricalAwards=false
• 关键词: CAREER; Warm; Quantum; Materials; Harnessing

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.

摘要：超导是凝聚态物理中最深奥的现象之一，具有完全无电阻的性质。在室温或接近室温的环境压力下实现超导状态是突破性的。压力已被证明是制造新材料（如超导体）时最通用的调谐参数。富氢材料，模拟氢的难以捉摸的固体金属相，可以在更低的压力下金属化，在更低的压力下促进高tc超导性。该项目的主要目标是在环境压力下合成新型富氢，室温或室温以上的超导材料，用于实际应用，如先进电网，新型交通，医学成像和扫描技术，如MRI和磁心图，以及更快，更高效的电子数字逻辑和存储设备技术。该项目还为高压实验提供了重要的研究基础设施，具有解决材料科学中各种问题的能力。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，他们可以使用大型用户设施并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；为第一代大学生、低收入和少数族裔学生提供研究机会；改善和建立聋人社区可用的资源。技术摘要：量子材料的特性对外部刺激（如压力）异常敏感，从而产生奇异的、通常是前所未有的特性。长期以来，人们对室温或高温超导性的追求，因在一种新型致密富氢材料——超氢化物中发现了高Tc超导性而重新焕发了活力。超氢化物依赖于氢分子的解离作用，它提供了费米能级附近能量状态所需的额外电子。然而，迄今为止，理论和实验研究主要集中在二元超氢化物上。本项目所设想的努力代表了一个自然而及时的研究方向，即发现和理解Tc可与室温相当或高于室温的新型三元和四元超导体的结构，化学键和稳定性，并通过成分调谐，降低转变压力同时保持超导性能。此外，为了了解这些热超导体的量子性质，在高压实验中需要对绝对温度进行测量。为了弥补这一需求，氮空位中心提供了一种新的方法来确定Mbar范围内压缩材料的原位温度测量，这将是革命性的。仔细的热测量可能会增加测量超导超氢化物的热容量的能力，这是超导性的一种优越测试。这项工作将使研究小组能够更广泛地了解超导性，包括稳定性，以及为变革技术设计一类新的热量子材料。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。