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

职业：非均匀超导体和超流体的理论和建模

• 批准号: 0954342
• 负责人: Anton Vorontsov
• 金额: $ 42万
• 依托单位: Montana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0954342&HistoricalAwards=false
• 关键词: CAREER; Theory; Modelling; Non; Uniform

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.

该职业奖支持理论和计算研究和教育，以研究非均匀超导态及其在新型超导体和超流氦-3中的起源。非均匀态的出现是由于多个能量尺度的复杂相互作用，导致准粒子谱的强烈局部修改，宏观上，具有新的对称性的状态。这些态在强关联材料、竞争有序系统以及小尺寸器件的界面区域中发挥着重要作用。对具有更高临界温度和更好材料特性的超导体的研究导致了具有奇异性质的复杂材料的新家族的发现。除了超导性，大多数显示某种磁序，这可能会显着影响超导性质，并可能提供或有助于配对相互作用，导致超导性。类似的行为也可以在受限几何中的自旋三重态超流氦-3中观察到。实验发现了许多新的非均匀凝聚相，本研究将集中于展示重费米子材料、无反转中心超导体、FeAs-磷属元素化物和超流氦-3薄膜中的非均匀态的全面图景。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。该项目将促进对物质新超导态性质的理解，并有助于将理论与实验联系起来。理论和数值方法将基于超导理论的准经典公式，其中包括磁自由度，多带和显着的自旋效应。本研究结果将有助于实现具有超导界面的超导体基器件。磁活性超导表面的研究可能会影响新的电荷和自旋耦合电子学的出现。这项研究激发了对最有影响力的物理学原理的展示，例如多粒子系统中的对称性和新兴复杂性。这构成了教育部分的基础，其中涉及研究生和本科生水平的新课程的开发，以及教育网站的开发，该网站具有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。非技术总结该职业奖支持理论和计算研究和教育，以调查材料中超导性的性质，它们是高度不均匀的，具有特殊的原子排列，或者显示出磁性和超导性之间的相互作用。超导性是电子的一种特殊状态，可以在足够低的温度下发生在某些材料中。与普通电线不同，例如铜，超导体可以携带电流而不会耗散。超导体还有其他一些不寻常的特性，使它们在未来的电子器件技术中有很好的应用前景。这项研究将探索材料和传导，在这种材料和传导下，超导性可以变化，或者可以在同一材料中从一种超导状态改变到另一种超导状态，例如响应磁序区域。这项研究可能会预测超导体和超流体中的新现象。超流体将超导性的概念从材料中的电子推广到液态，例如在接近绝对零度的温度下发生在液氦中的超导体。超导性和更一般的超流性是一种有趣的物质状态，需要量子力学描述，不仅在发现新的超导状态和现象方面，而且在其潜在的应用方面，例如在新的电子设备和电力传输方面，都保持着丰富的智力。这项研究激发了凝聚态物理学中一些最强大的原理的演示，例如多粒子系统中的对称性和新兴复杂性。它还构成了教育部分的基础，其中涉及在研究生和本科生两个层次的新课程的发展，并与图形演示和链接到其他物理，化学和生物研究在蒙大拿州立大学的教育网站的发展。