High Temperature, Topological Superconductivity via the Proximity Effect

该奖项来自材料研究部凝聚态物理项目，支持波士顿大学的一个项目，该项目利用最近开发的接近技术探索在材料中诱导超导性的新方法。超导是一种物质的状态，在这种状态下，电子在没有摩擦的情况下携带电，当材料冷却到某一临界温度以下时就会发生。超导状态，具有相对“高”的转变温度（略高于液氮的温度），可以通过改变一系列磁性材料的化学性质来诱导。然而，这涉及到同时更改多个参数，使分析变得复杂。该项目采用了另一种方法，即通过“接近”来诱导超导性，即将超导体与非超导（正常）材料极好地接触，在那里可以调整界面和正常状态属性。该项目探索了控制邻近诱导超导状态出现的普通材料的各个方面。这将使系统的研究成为可能，并为追求难以捉摸的马约拉纳费米子提供了一个平台。为实现这一目标，各级学生，从高中到博士后，将学习各种技术（器件制造和表征）到专业技能（培训、项目管理）。技术摘要：该项目旨在生成新的物质状态，同时推动我们在有序参数和拓扑耦合方面的知识边界。这将通过由首席研究员开发的一种新的机械键合技术来实现，这为在半导体、半金属和拓扑绝缘体中创造和操纵非常规超导打开了大门。这些新平台将结合光学和传输技术来探索，以解决基本问题和技术挑战，例如：观察高Tc超导邻近效应的最佳条件是什么？带结构、载流子密度和拓扑结构如何影响超导性的产生？超导序参量的对称性如何受到基体材料的影响？重点将放在高温超导体Bi2Sr2CaCu2O（8+y）与MoS2， Bi2Te2Se和石墨/石墨烯的组合上。各级学员将参与器件的制造和光学/差分电导数据的分析，学习各种分析、器件制造和表征技术，以及专业技能。

Non-Technical AbstractThis award from the Condensed Matter Physics program of the Division of Materials Research supports Boston University with a project to explore new approach to induce superconductivity in a material using a recently developed proximity technique. Superconductivity, a state of matter in which electrons carry electricity without friction, occurs when a material is cooled below a certain critical temperature. Superconducting states, with relatively "high" transition temperatures (just above that of liquid nitrogen), can be induced by changing the chemistry of a series of magnetic materials. However, this involves changing multiple parameters simultaneously, complicating the analysis. This project follows an alternative approach which is to induce superconductivity via "proximity", namely placing a superconductor in excellent contact with a non-superconducting (normal) material, where the interface and normal state properties can be tuned. The project explores the various aspects of the normal materials that control the emergence of the proximity induced superconducting state. This will enable systematic studies and provide a platform for pursuing the elusive Majorana fermions. To achieve this students of all levels, high school to postdoctoral trainees, will learn a variety of technical (device fabrication and characterization) to professional skills (training, project management). Technical AbstractThis project is to generate new states of matter, while pushing the boundaries of our knowledge on the coupling of order parameters and topology. This will be achieved using a new mechanical bonding technique developed by the principal investigator, which opens the door to creating and manipulating unconventional superconductivity in semiconductors, semimetals and topological insulators. These new platforms will be explored using a combination of optical and transport techniques to address fundamental questions and technical challenges such as: What are the optimum conditions for observing a high Tc superconducting proximity effect? How do band structure, carrier density and topology affect the emergence of superconductivity? How is the symmetry of the superconducting order parameter affected by the host material? Particular focus will be given to the high temperature superconductor Bi2Sr2CaCu2O(8+y) in combination with MoS2, Bi2Te2Se, and Graphite/Graphene. Trainees at all levels will be involved in the fabrication of devices and the analysis of optical/differential conductance data, to learn a variety of analysis, device fabrication and characterization techniques, as well as professional skills.