Topological Hysteresis, Structure and Nucleation of the Intermediate State in Type-I Superconductors

超导中间态是在元素（I型）超导体中形成的正常区和超导区的复杂模式。新发展的实验技术可能会导致我们目前对这种状态的理解的实质性修订。这些技术允许人们在真实的时间内观察中间态的局部磁场，并以极高的灵敏度测量它们。这项研究与复杂的数学、地球物理、化学和生物系统中图案形成的重要问题，甚至与星系的形成有关。该项目具有重大的教育影响。所有级别的学生都将参与这个项目，每个人都要完成一组特定的测量。一些实验将成为高级固体物理实验室的一部分。该项目涉及积极的国内和国际合作与领先的专家在该领域，包括那些谁发起了相关的研究几十年前。计划在研究期末举办一个关于I型超导体中图形形成的研讨会。技术摘要这个个人研究者奖将支持I型超导体中中间态的综合研究。独特的实验技术，如磁场的磁光可视化和pico-emu敏感的隧道二极管磁阻测量，结合传统的方法，将被用来理解在高度非线性系统中更广泛的图案形成背景下的中间状态。拓扑滞后和复杂形状效应的研究可能会导致不寻常的超导平衡态的识别，并最终导致我们目前对I型超导性的理解的实质性修订。利用温度和磁场在广泛的拓扑结构范围内连续调节系统的能力使I型超导成为研究非线性系统中图案形成的一般问题的理想竞技场。作为该项目的一部分，将研究与生物、化学和天体物理系统的联系，该项目具有重大的教育影响。所有级别的学生都将参与该项目，每个人都将执行特定的测量。一些实验将成为高级固体物理实验室的一部分。该项目涉及积极的国内和国际合作与领先的专家在该领域，包括那些谁发起了相关的研究几十年前。本研究期末将举办一个关于第一类超导体中图形形成的研讨会。

Non-technical abstractThe superconducting intermediate state is formed in elemental (type-I) superconductors as acomplex pattern of normal and superconducting regions. Newly developedexperimental techniques may lead to a substantial revision of our currentunderstanding of this state. These techniques allow one to observe localmagnetic fields of the intermediate state in real time and to measure themwith extreemly high sensitivity. This research has connections to importantquestions of pattern formation in complex mathematical, geophysical,chemical and biological systems and even to the formation of galaxies. Theproject carries significant educational impact. Students of all levels willwork on the project, each performing specific set of measurements. Someexperiments will be part of the advanced solid-state physics laboratory. Theproject involves active domestic and international collaborations with theleading experts in the field, including those who initiated related studiesdecades ago. A workshop on pattern formation in type-I superconductors isplanned at the end of the research term.Technical abstractThis individual investigator award will support comprehensive studies of theintermediate state in type-I superconductors. Unique experimentaltechniques, such as magneto-optical visualization of magnetic fields andpico-emu sensitive tunnel-diode susceptometry, combined with conventionalmethods, will be employed to understand the intermediate state in a broadercontext of pattern formation in highly nonlinear systems. The study oftopological hysteresis and complex shape effects may lead to theidentification of unusual thermodynamically equilibrium states and,ultimately, to substantial revisions of our current understanding of type-Isuperconductivity. The ability to continuously tune the system across abroad range of topologies using both temperature and magnetic field makestype-I superconductivity an ideal arena in which to study general questionsof pattern formation in nonlinear systems. Connections to biological,chemical and astrophysical systems will be studied as part of this project.The project carries significant educational impact. Students of all levelswill work on the project, each performing specific set of measurements. Someexperiments will be part of the advanced solid-state physics lab. Theproject involves active domestic and international collaborations with theleading experts in the field, including those who initiated related studiesdecades ago. A workshop on pattern formation in type-I superconductors isplanned at the end of the research term.