Manipulating 2D Superconductivity through atomic scale control of boundary conditions

通过边界条件的原子尺度控制来操纵二维超导

• 批准号: 1506678
• 负责人: Chih-Kang Shih
• 金额: $ 38.28万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1506678&HistoricalAwards=false
• 关键词: Manipulating; 2D; Superconductivity; through; atomic

NON-TECHNICAL ABSTRACT:This proposal is aimed at controlling the properties of thin superconductor films in the range of only a few atomic monolayers and studying the superconducting properties in this new regime. The superconducting films in such a thin regime are likely to exhibit properties that are not found in the bulk form. For example, such a thin film may be able to carry supercurrent in the presence of very high magnetic fields making the film much more useful for device applications. The research activities involve state-of-the-art synthesis techniques that can lay down the thin film atomic layer by atomic layer thus enabling us to achieve the ultimate material control at the microscopic scale. In addition, we will use characterization tools to study the superconducting properties from nanometer to macroscopic (millimeter) length scales. The proposal focuses on the integration of research and education to train internationally competitive students in materials research. We are also committed to educational outreach to broader audiences at all levels. At UT-Austin the PI will take advantage of the Summer Academy of Nanoscience and Nanotechnology for state-wide high school teachers and students, previously established under the IGERT program. Moreover, we will offer summer internship opportunities for female high school students through the Alice in the Wonderland program; the PI has already hosted four of these students as summer interns and will continue to do so in future years. Finally, this program is fully committed to broadening participation of under-represented groups in graduate research with specific goals of increasing the percentage of graduate students that are women or/and of Hispanic background. TECHNICAL ABSTRACT:Elegantly fabricated functional materials with reduced dimensions occupy a central stage of modern materials research. Supported by an NSF-FRG program in the past, the PI has been focusing on the novel physical properties of precisely tailored metallic thin films and related nanostructures in the quantum regime. These past efforts have substantially advanced the field in terms of growth and characterization of such structures. In the proposed program, we will take another leap forward by creating new heterostructures based on these quantum films to explore and harness their emergent exotic superconducting properties for potential applications. Specifically, we will focus on the interplay of superconductivity with three different quantum degrees of freedom, including electronic, lattice, and spin, and we will implement the following four major task areas: (a) Correlating microscopic and macroscopic measurements - manipulating structural defects and investigating their roles on phase fluctuations; (b) Revisiting quantum size effect on superconductivity ultra-thin films and unraveling the quantum confinement of phonons; (c) Tuning superconductivity of atomic-layer superconducting films with interfacial engineering; and (d) Exploring superconducting - spin-paramagnetic (SC-SP) transition in ultra-thin epitaxial films.

非技术摘要：该提案旨在将超导薄膜的性能控制在仅几个原子单层的范围内，并研究这种新状态下的超导性能。 如此薄的超导薄膜很可能表现出块状超导薄膜所没有的特性。 例如，这样的薄膜可能能够在非常高的磁场存在下承载超电流，使得该薄膜对于设备应用更加有用。 研究活动涉及最先进的合成技术，可以逐层沉积薄膜原子层，从而使我们能够在微观尺度上实现最终的材料控制。 此外，我们将使用表征工具来研究从纳米到宏观（毫米）长度尺度的超导特性。 该提案的重点是研究和教育的结合，培养具有国际竞争力的材料研究学生。 我们还致力于向各个级别的更广泛受众进行教育推广。 在 UT-Austin，PI 将利用之前根据 IGERT 计划建立的面向全州高中教师和学生的纳米科学和纳米技术夏季学院。 此外，我们还将通过爱丽丝梦游仙境项目为女高中生提供暑期实习机会； PI 已经接待了其中四名学生作为暑期实习生，并将在未来几年继续这样做。 最后，该计划完全致力于扩大代表性不足的群体对研究生研究的参与，具体目标是增加女性或/和西班牙背景研究生的比例。技术摘要：精心制作的尺寸减小的功能材料占据了现代材料研究的中心舞台。在过去 NSF-FRG 项目的支持下，PI 一直专注于量子领域中精确定​​制的金属薄膜和相关纳米结构的新颖物理特性。过去的这些努力在此类结构的生长和表征方面极大地推进了该领域的发展。在拟议的计划中，我们将通过基于这些量子薄膜创建新的异质结构来探索和利用其新兴的奇异超导特性来实现潜在的应用，从而实现另一次飞跃。 具体来说，我们将重点关注超导与三个不同量子自由度（包括电子、晶格和自旋）的相互作用，我们将实施以下四个主要任务领域：（a）关联微观和宏观测量——操纵结构缺陷和研究它们对相位波动的作用； (b) 重新审视超导超薄膜的量子尺寸效应并解开声子的量子限制； (c) 利用界面工程调节原子层超导薄膜的超导性； (d) 探索超薄外延膜中的超导-自旋顺磁（SC-SP）转变。