CAREER: Theory and Modelling of Non-Uniform Superconductors and Superfluids

技术总结这个职业奖项支持理论和计算研究和教育，以研究新型超导体和超流氦-3中的非均匀超导态及其起源。非均质态的出现是由于多个能量尺度的复杂相互作用，导致准粒子光谱的强烈局域修正，以及宏观上具有新对称性的态。这种状态有望在强关联材料、有序竞争系统和小型器件的界面区域中发挥重要作用。对具有更高临界温度和更好材料特性的超导体的探索导致了具有奇异性质的新的复合材料族的发现。除了超导电性之外，大多数都表现出某种磁序，这可能会显著影响超导性质，并可能提供或促成导致超导的配对相互作用。在受限几何中的自旋三重态超流体氦-3中也可能观察到类似的行为。实验发现了许多被认为是非均匀的新的凝聚态。这项研究将集中于呈现重费米子材料、无反转中心的超导体、FeAs多晶石和超流氦-3薄膜中的非均匀状态的综合图景。将研究这些系统中的新状态及其热力学、输运和磁性，包括强耦合和非平衡现象。这个项目将促进对物质新的超导状态的本质的理解，并有助于将理论和实验联系起来。理论和数值方法将基于超导理论的准经典公式，该理论将包括磁自由度、多带和显著的自旋效应。这一研究结果可能有助于实现具有超导界面的超导体器件。磁活性超导表面的研究可能会影响新的电荷耦合和自旋耦合电子学的出现。这项研究启发了最具影响力的物理学原理的演示，例如对称性和多粒子系统中新出现的复杂性。这构成了教育部分的基础，包括开发研究生和本科水平的新课程，以及开发一个带有图形演示和链接到蒙大拿州立大学进行的其他物理、化学和生物研究的教育网站。非技术总结这个职业奖项支持理论和计算研究和教育，以调查材料中超导的性质，这些材料高度不均匀，具有特殊的原子排列，或显示磁性和超导之间的相互作用。超导性是电子的一种特殊状态，它可以在足够低的温度下出现在某些材料中。与铜制的普通导线不同，超导体可以不耗散地携带电流。超导体还有其他不同寻常的特性，这使得它们在未来的电子设备技术中有很好的应用前景。这项研究将探索超导电性可以在同一材料中从一个超导状态改变到另一个超导状态的材料和导体，例如，响应于磁序区。这项研究可能会预测超导体和超流体中的新现象。超流体将物质中电子以外的超导电性概念推广到液体状态，例如，在温度接近绝对零度时出现在液氦中的超导电性。超导性和更广泛的超流性是一种有趣的物质状态，需要量子力学描述，不仅在智力上发现新的超导状态和现象，而且还具有潜在的应用，例如在新的电子设备和电力传输中。这项研究启发了凝聚态物理学中一些最强大的原理的演示，例如对称性和多粒子系统中新出现的复杂性。它还构成教育部分的基础，涉及在研究生和本科阶段开发新的课程，并开发一个教育网站，提供图形演示和与蒙大拿州立大学进行的其他物理、化学和生物研究的链接。

TECHNICAL SUMMARYThis CAREER award supports theoretical and computational research and education to investigate non-uniform superconducting states and their origin in novel superconductors and superfluid helium-3. Inhomogeneous states appear due to a complex interplay of multiple energy scales that lead to strong local modification of the quasiparticle spectrum and, macroscopically, to states with new symmetries. Such states are expected to play major roles in strongly correlated materials, systems with competing orders, and in the interface regions of small-scale devices.The search for superconductors with higher critical temperature and better material characteristics has led to the discovery of new families of complex materials with exotic properties. Besides superconductivity, most display some kind of magnetic order which may significantly influence superconducting properties, and may provide or contribute to the pairing interaction that leads to superconductivity. Similar behavior may have also been observed in spin-triplet superfluid helium-3 in confined geometries. Experiments suggest many new condensate phases that are thought to be non-uniform.This research will focus on presenting a comprehensive picture of non-uniform states in heavy fermion materials, superconductors without inversion center, FeAs-pnictides, and superfluid helium-3 films. New states and their thermodynamic, transport and magnetic properties will be studied in these systems, including strong-coupling and non-equilibrium phenomena. This project will advance understanding of the nature of new superconducting states of matter and help to link theory and experiment. The theoretical and numerical approach will be based on a quasiclassical formulation of the theory of superconductivity that will include magnetic degrees of freedom, multiple bands, and significant spin effects. The results of this research may contribute to the realization of superconductor-based devices with superconducting interfaces. The study of magnetically active superconducting surfaces may influence appearance of new charge- and spin-coupled electronics. The research inspires demonstrations of the most influential principles of physics, such as symmetry and emerging complexity in many-particle systems. This forms the basis of the education component which involves the development of new courses on both graduate and undergraduate levels, and the development of an educational website with graphical demonstrations and links to other physics, chemistry and biological research conducted at Montana State University.NONTECHNICAL SUMMARYThis CAREER award supports theoretical and computational research and education to investigate the nature of superconductivity in materials, that are highly non-uniform, have special arrangements of atoms, or display an interplay between magnetism and superconductivity. Superconductivity is an extraordinary state of electrons that can occur in some materials at sufficiently low temperatures. Unlike common wires made of, for example, copper, a superconductor can carry electric current without dissipation. Superconductors have other unusual properties that make them promising for applications in future electronic device technologies. This research will explore materials and conductions under which superconductivity can vary or can change from one superconducting state to another in the same material, for example in response to regions of magnetic order. This research may predict new phenomena in superconductors and in superfluids. Superfluids generalize the concept of superconductivity beyond electrons in a material to liquid states, for example those that that occur in liquid helium at temperatures approaching absolute zero. Superconductivity and more generally superfluidity is an intriguing state of matter that requires a quantum mechanical description and remains fertile not only intellectually in the discovery of new superconducting states and phenomena, but also for its potential applications, for example in new electronic devices and power transmission. This research inspires demonstrations of some of the most powerful principles of condensed matter physics, such as symmetry and emerging complexity in many-particle systems. It also forms the basis of the education component which involves the development of new courses at both graduate and undergraduate levels, and the development of an educational website with graphical demonstrations and links to other physics, chemistry and biological research conducted at Montana State University.