Fundamental Properties of Superconductors and Mesoscale Devices

超导体和介观尺度器件的基本特性

• 批准号: 0244441
• 负责人: Michael Tinkham
• 金额: $ 42万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0244441&HistoricalAwards=false
• 关键词: Fundamental; Properties; Superconductors; Mesoscale; Devices

This Condensed Matter Physics project, involving experiment and data analysis, and theoretical modeling, will study the physical properties of nanoscale device structures, fabricated of superconducting, normal metal, ferromagnetic, and organic conductors. One of the most active issues in fundamental research in superconductivity is clarification of how superconductivity is weakened and eventually destroyed by quantum phase-slip processes in a superconducting wire as it is made thinner and thinner, approaching the true one-dimensional limit. This issue also has potential practical importance in setting a limit on miniaturization of superconductive electronics. Experiments involving controlled external damping are planned to clarify the role of dissipative processes in suppressing quantum phase slips, and perhaps driving a phase transition at T = 0 to a truly zero resistance state. The effect of heating on I-V characteristics at finite current levels also needs to be understood. Other planned experiments study charge and spin transfer between ferromagnetic and superconducting metals in geometries involving nanometer length scales. Such experiments probe the length scales required for possible applications in quantum computing and tests of Bell's inequality. Research will also be done on carbon nanotubes, using Raman scattering to determine the chirality of individual nanotubes used in transport and scanned probe measurements, to eliminate a major source of uncertainty in the interpretation of experimental data. Students and postdocs involved in this project will become expert in techniques of fabrication and measurement of nanostructures, essential to development of modern technology.Experimental measurements and theoretical analysis will be carried out to increase our understanding of the physical properties of nanoscale device structures fabricated of a wide range of materials: superconducting, normal metal, ferromagnetic, and organic. In addition to the pursuit of scientific knowledge and intellectual understanding, this work will have broader impact in two separate directions: (1) Understanding of the unique quantum properties of materials when their dimensions are reduced to the nanometer scale is essential to exploiting opportunities and avoiding barriers to technological progress as the miniaturization epitomized by Moore's Law proceeds in the future. (For example, a superconducting wire becomes resistive if its diameter is reduced too much.); (2) Researchers in this program (ranging from undergraduates to postdocs and visiting faculty) receive thorough exposure to a wide range of fabrication, measurement, and interpretation skills, which provides excellent preparation for careers in academia, industry, and government.

该凝聚的物理项目涉及实验和数据分析以及理论建模，将研究由超导，正常金属，铁磁和有机导体制造的纳米级设备结构的物理性质。 超导性基础研究中最活跃的问题之一是阐明超导性如何削弱，并最终被超导电线中的量子相距过程破坏，因为它变得越来越薄，接近真正的一维极限。 这个问题在设定超导电子的小型化方面也具有潜在的实际重要性。 计划涉及受控外部阻尼的实验，以阐明耗散过程在抑制量子相滑中的作用，并可能在t = 0处将相变为真正的零电阻状态。 还需要了解加热对有限电流水平的I-V特性的影响。 其他计划的实验研究了涉及纳米长度尺度的几何形状中的铁磁和超导金属之间的电荷和自旋转移。 这样的实验探测了量子计算中可能应用所需的长度尺度和对贝尔不等式的测试。 还将对碳纳米管进行研究，并使用拉曼散射来确定用于运输和扫描探针测量的单个纳米管的手性，以消除实验数据解释的主要不确定性。参与该项目的学生和博士后将成为制造和测量纳米结构技术的专家，这对于现代技术的开发至关重要。实验测量和理论分析以增进我们对纳米级设备结构的物理特性的理解，这些纳米级设备结构构成了各种材料范围的范围：超管制，正常金属，ferromagnetic，ferromagn和Organsic和Organsic和Organsic和Organsic。 除了追求科学知识和智力理解之外，这项工作还将在两个单独的方向上产生更大的影响：（1）当材料尺寸降低到纳米量表时，了解材料的独特量子特性对于避免机遇并避免了技术进步的障碍至关重要，因为摩尔法律在未来的法律中表现出了微小化的迹象。 （例如，如果直径过多，则超导线将具有电阻。）； （2）该计划的研究人员（从本科生到博士后再到访问教师）彻底接触了广泛的制造，测量和解释技能，这为学术，工业和政府的职业提供了出色的准备。