Using Disorder to Detect Local Order: Noise and Nonequilibrium Effects of Stripes in the Presence of Quenched Disorder

使用无序检测局部有序：存在淬灭无序时条纹的噪声和非平衡效应

• 批准号: 0804748
• 负责人: Erica Carlson
• 金额: $ 24万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0804748&HistoricalAwards=false
• 关键词: Using; Disorder; Detect; Local; Order

TECHNICAL SUMMARY:This award supports theoretical research and education on strongly correlated electron materials with a focus on spontaneous electronic pattern formation at the nanoscale. The PI will develop new ways of studying materials, explicitly including disorder, and using noise, nonequilibrium effects, and mesoscopic geometries in order to elucidate the local electronic patterns. For example, stripes (like other proposed real space orders) may be important for high temperature superconductivity, but they have only been observed in a subset of cuprate superconductors, most notably in cases where the stripes exhibit true long-range order. However, even disordered or slowly fluctuating stripes (invisible to many standard bulk probes) are sufficient for a stripes-based mechanism of high temperature superconductivity. The PI recently mapped the problem of disordered stripes to the random field Ising model. The PI will use simulations on this model to make predictions about how to detect disordered stripes using noise and nonequilibrium effects in, e.g., transport, STM, neutron scattering, and magnetic hysteresis.This award also supports the PI?s efforts to continue to develop the mentoring program she began for graduate women in the physics program at her home institution, by initiating a program to invite graduate physics alumnae back to campus to discuss career options with current graduate and undergraduate students in physics. The PI will also continue to visit local high schools to discuss her research. This outreach combines interactive hands-on superconductivity demonstrations with education about contemporary condensed matter research. In addition, the proposed work will advance the training of one graduate student and two postdoctoral associates.NON-TECHNICAL SUMMARY:This award supports theoretical research and education aimed at understanding fundamental questions raised in the study of high temperature superconductors. These are materials that can transport electric current without loss at sufficiently low temperatures. The physical mechanism by which electrons enter this cooperative quantum mechanical state of superconductivity remains a subject of intense research for the high temperature superconductors. These materials exhibit superconductivity at much higher temperatures, but still well below room temperature, than the much better understood superconducting materials that one might encounter in a medical magnetic resonance imaging machine. Understanding the mechanism for superconductivity may lead to the discovery or engineering of materials that exhibit superconductivity at still higher temperatures, with the possibility of enabling economical new technologies for power transmission and new electronic devices. The research will focus on an interesting aspect of the puzzle, the spatially varying patterns of characteristic quantum mechanical properties of electrons that have been observed in experiments on some high temperature superconductors.This award also supports the PI?s efforts to continue to develop the mentoring program she began for graduate women in the physics program at her home institution, by initiating a program to invite graduate physics alumnae back to campus to discuss career options with current graduate and undergraduate students in physics. The PI will also continue to visit local high schools to discuss her research. This outreach combines interactive hands-on superconductivity demonstrations with education about contemporary condensed matter research. In addition, the proposed work will advance the training of one graduate student and two postdoctoral associates.

技术摘要：该奖项支持强相关电子材料的理论研究和教育，重点是纳米级自发电子图案的形成。 PI 将开发研究材料的新方法，明确包括无序性，并利用噪声、非平衡效应和介观几何形状来阐明局部电子模式。例如，条纹（像其他提出的实空间序一样）可能对高温超导性很重要，但它们仅在铜酸盐超导体的子集中观察到，最明显的是在条纹表现出真正的长程有序的情况下。然而，即使是无序或缓慢波动的条纹（许多标准体探针不可见）也足以实现基于条纹的高温超导机制。 PI 最近将无序条纹问题映射到随机场 Ising 模型。 PI 将使用该模型的模拟来预测如何使用噪声和非平衡效应（例如传输、STM、中子散射和磁滞）来检测无序条纹。该奖项还支持 PI 继续开发的努力她为所在机构的物理专业女研究生启动了指导计划，发起了一项邀请物理系研究生回到校园与当前物理系研究生和本科生讨论职业选择的计划。 PI 还将继续访问当地高中讨论她的研究。该活动将互动式超导实践演示与当代凝聚态物质研究教育结合起来。此外，拟议的工作将促进一名研究生和两名博士后的培训。非技术摘要：该奖项支持旨在理解高温超导体研究中提出的基本问题的理论研究和教育。这些材料可以在足够低的温度下传输电流而不损失。电子进入超导协同量子力学状态的物理机制仍然是高温超导体深入研究的课题。与人们在医学磁共振成像机中可能遇到的更容易理解的超导材料相比，这些材料在更高的温度下表现出超导性，但仍远低于室温。了解超导机制可能会导致发现或设计在更高温度下表现出超导性的材料，并有可能为电力传输和新电子设备提供经济的新技术。该研究将集中于这个难题的一个有趣的方面，即在一些高温超导体的实验中观察到的电子特征量子力学特性的空间变化模式。该奖项还支持 PI 继续开发指导的努力她在自己所在的机构为物理学专业的女研究生启动了一项计划，邀请物理系的研究生校友回到校园与当前的物理系研究生和本科生讨论职业选择。 PI 还将继续访问当地高中讨论她的研究。该活动将互动式超导实践演示与当代凝聚态物质研究教育结合起来。此外，拟议的工作将促进一名研究生和两名博士后的培训。