EAPSI:Investigation of the Unconventional Superconducting Mechanism in Li0.9Mo6O17

新材料的发现和理解推动了计算机时代的技术发展。对半导体性质的研究为现代计算机电子学奠定了基础。对金属和绝缘体的更好理解使微加工和节能技术成为可能。超导体的发现给人们带来了不损失能量的电能传输的希望。该项目研究了一种奇异的超导材料，Li0.9Mo6O17，由京都大学非传统超导体领域的主要科学家之一Yuji Matsuda教授负责。这种材料显示出一些不寻常的低维特性，这些特性还没有被很好地理解。这个项目将用一根尖锐的针头探测这种材料，这种针头的尖端只由几个原子组成，从而澄清这些不寻常的特性。通过在极冷的环境中通电，可以揭示Li0.9Mo6O17的超导性质。更好地了解这种材料的性质将导致非常规超导体领域的进步，并有望影响电子和计算的未来。拟研究的目的是确定准一维晶体Li0.9Mo6O17的超导机理。这种晶体被认为是一种卢廷格液体，一种奇异的物质状态，电子分离成独立的电荷和自旋波。在正常状态下对Li0.9Mo6O17进行了许多研究，揭示了令人兴奋的新物理学。然而，对于Li0.9Mo6O17的超导态，仍有许多有待了解的地方。有一些证据表明Li0.9Mo6O17是一种非常规的自旋三重态超导体，但尚未对超导间隙进行详细的研究，以阐明超导机理。在Matsuda Yuji教授的指导下，PI将在超导状态下生长高质量的Li0.9Mo6O17单晶并进行扫描隧道显微镜（STM）。为了在超导状态下对Li0.9Mo6O17进行首次STM测量，PI将使用3He制冷的STM。超导间隙的STM研究将揭示Li0.9Mo6O17是否符合非常规自旋三重态超导或其他机制。该奖项隶属于东亚和太平洋暑期研究所项目，由美国国家科学基金会和日本科学促进会共同资助，支持一名美国研究生进行暑期研究。

The discovery and understanding of new materials has driven technology development in the computer age. Research on the properties of semiconductors has laid the foundation for modern computer electronics. Better understanding of metals and insulators has enabled micro-fabrication and energy efficient technology. The discovery of the superconductor has lead to the hope of power transfer without energy loss. This project investigates an exotic superconducting material, Li0.9Mo6O17, under one of the leading scientists in the field of unconventional superconductors, Professor Yuji Matsuda from Kyoto University. This material shows some unusual low-dimensional properties that are not well understood. This project will clarify those unusual properties by probing the material with a sharp needle, which has a tip consisting of only a few atoms. By running electricity through the needle in a very cold environment, the nature of superconductivity in Li0.9Mo6O17 can be revealed. Better understanding of this material's properties will lead to an advancement of the field of unconventional superconductors and has promise to impact the future of electronics and computing.The objective of the proposed research is to determine the superconducting mechanism of the quasi-1D crystal Li0.9Mo6O17. This crystal has been proposed to be a Luttinger Liquid, an exotic state of matter where the electrons separate into independent charge and spin waves. Many studies have been done on Li0.9Mo6O17 in the normal state revealing exciting new physics. However, there is still much to be learned about the superconducting state of Li0.9Mo6O17. There is some evidence suggesting that Li0.9Mo6O17 is an unconventional spin-triplet superconductor, but a detailed study of the superconducting gap, which would elucidate the superconducting mechanism, has not been done. The PI, under the mentorship of Professor Yuji Matsuda, will grow high quality single crystal Li0.9Mo6O17 and perform Scanning Tunneling Microscopy (STM) in the superconducting state. To perform the first STM measurements of Li0.9Mo6O17 in the superconducting state, the PI will employ STM with 3He refrigeration. An STM study of the superconducting gap will reveal if Li0.9Mo6O17 behaves according to unconventional spin-triplet superconductivity or some other mechanism.This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.