CAREER: Superconductivity in Lithium-Rich Compounds

富锂化合物的超导电性非技术摘要：超导体具有零电阻率和完美的抗磁性，在能量存储、传输、医疗和运输方面有着巨大的应用前景。遗憾的是，目前已知的所有超导体的工作温度都太低，不适合大规模应用。轻质材料在高温下具有良好的超导性能。这项研究的重点是寻找由超轻材料组成的新的超导系统，重点是了解轻元素中相当重要的非经典晶格动力学。我们将特别关注富锂(最轻的金属和超导元素)的材料，并利用极端压力条件寻找新的富锂高温超导系统。技术摘要：锂是最轻的金属和超导元素。对于氢的金属相，理论上考虑了压缩轻金属系统中奇异量子态的出现。金属氢被预测为液体基态，并可能表现出双组分超流和超导相。然而，将氢压缩到足以金属化的密度是困难的，这阻碍了这些效应的实验证明。作为研究密集轻金属系统中晶格量子效应演化的另一种途径，本研究将研究锂在加压下与氢等价的结构和电子性质。由于其质量轻，Li的晶格是高度动态的，为电子-声子耦合提供了很大的声子谱。通过化学修饰，有可能通过电子增强来获得高超导转变温度的富Li化合物。这项研究的动机是利用高压技术系统地研究超轻锂基化合物的超导电性。研究富锂化合物的超导相图将有助于寻找通过化学修饰来提高超导电性的方法。

Superconductivity in Lithium-rich compounds Non technical abstract: Superconductors, which have zero electrical resistivity and perfect diamagnetism, hold great promise for applications in energy storage, transmission, medical applications and transportation. Unfortunately, the operating temperature of all currently known superconductors is too low for large scale applications. Light materials have been considered to be promising for exhibiting superconducting properties at high temperature. This research focuses on finding new superconducting systems made of ultra light materials with a focus on understanding the non-classical lattice dynamics which are considerable in light elements. We will specifically focus on materials rich in lithium (the lightest metal and superconducting element) and search for new lithium-rich high temperature superconducting systems utilizing extreme conditions of pressure.Technical abstract: Lithium is the lightest metal and superconducting element. The emergence of exotic quantum states in a compressed light metallic system has been entertained theoretically for metallic phases of hydrogen. Metallic hydrogen is predicted to have a liquid ground state, and may exhibit a two component superfluid and superconducting phase. The difficulty of compressing hydrogen to densities sufficient for metallization, however, has prevented experimental proof of these effects. As an alternative route to studying the evolution of lattice quantum effects in a dense light metallic system, this study will investigate the structural and electronic properties of lithium which is isovalent to hydrogen under pressure. Due to its light mass, Li's lattice is highly dynamic, providing a large phonon spectrum for electron-phonon coupling. By chemical modification, it may be possible to synthesize a Li rich compound in which a high superconducting transition temperature is achieved through electronic enhancement. The motivation of this research is to systematically study superconductivity in ultra-light lithium-based compounds by using high pressure techniques. Studying the superconducting phase diagram of Li-rich compounds will provide insight into finding ways which enhance the superconductivity by chemical modification.