Disentangling Pseudogap from Superconductivity in the Cuprates by Scanning Tunneling Microscopy

****技术摘要****高温超导体（HTS）中电子态的性质和行为是许多争论的中心。在超导转变温度以上观察到的赝隙态，被一些人看作是超导态的前兆。其他人则认为这是一个竞争阶段。尽管进行了大量的实验和理论工作，但这个问题仍然存在高度争议，并且是我们对高温超导的总体理解的核心。该个人研究者奖支持通过温度依赖扫描隧道显微镜（STM）对这种关系的研究。实验将在Bi2Sr2CuO6+x和YBa2Cu3O6+x中进行，前者我们之前已经观察到存在竞争相的证据，后者更常被研究，但尚未使用最近开发的STM技术进行研究。超高真空变温扫描隧道显微术是一项要求很高的实验技术；高温超导，作为强相关电子系统的一部分，是许多凝聚态物理的中心。因此，这个项目将是一个很好的训练学生的场所。此外，该奖项将支持科学推广到广泛的受众，这些受众受到高温超导的引人注目的科学奥秘和技术前景的推动。****非技术摘要****超导体是一种可以无电阻地传输电流的材料，可以通过产生热量而产生能量损失。不幸的是，这种技术上有用的特性只有在非常低的温度下才能开启，低于“转变温度”。就在二十多年前，一类新的“高温超导体”被发现，其转变温度接近100k。与室温（300 K）相比，这仍然是非常冷的，但已经导致了激烈的技术，如能源基础设施和科学发展。这项个人研究者奖支持对高温超导体的实验研究，目的是了解其在过渡温度（甚至在某些材料中高于室温）以上的非常规特性与超导性之间的关系。有人提出，这些较高的温度性质与超导性竞争或干扰，并且通过理解和控制它们可以显着提高转变温度。在研究这个建议的过程中，学生将接受广泛的实验技术训练。此外，高温超导的引人注目的科学奥秘和技术前景使科学推广到广泛的受众，也得到了该奖项的支持。

****TECHNICAL ABSTRACT****The nature and behavior of electronic states in high temperature superconductors (HTS) are the center of much debate. The pseudogap state, observed above the superconducting transition temperature, is seen by some as a precursor to the superconducting state. Others view it as a competing phase. Despite much experimental and theoretical work, this question remains highly debated and central to our understanding of HTS in general. This individual investigator award supports the investigation of this relationship by temperature dependent scanning tunneling microscopy (STM). Experiments will be performed in both Bi2Sr2CuO6+x, in which we have previously observed evidence for a competing phase, and YBa2Cu3O6+x, which is more commonly studied but has not been investigated with recently developed STM techniques. Ultrahigh vacuum, variable temperature scanning tunneling microscopy is a demanding experimental technique; HTS, as part of the broad class of strongly correlated electron systems, are at the center of much condensed matter physics. Hence this project will be an excellent training ground for students. Furthermore, this award will support science outreach to broad audiences driven by the compelling scientific mystery and technological promise of high temperature superconductivity.****NON-TECHNICAL ABSTRACT****Superconductors are materials that can carry current without resistance and resultant energy losses through heat generation. Unfortunately, this technologically useful property only turns on at very low temperatures, below a "transition temperature." Just over twenty years ago a new class of "High Temperature Superconductors" were discovered, with transition temperatures near 100 K. This is still very cold compared to room temperature (300 K), but has led to intense technological, such as energy infrastructure, and scientific development. This individual investigator award supports the experimental investigation of high temperature superconductors with the goal of understanding the relationship between their unconventional properties above the transition temperature (even above room temperature in some materials) and superconductivity. It has been proposed that these higher temperature properties compete, or interfere, with superconductivity, and that by understanding and controlling them transition temperatures may be significantly increased. While investigating this proposal, students will be trained in a wide range of experimental techniques. Furthermore, the compelling scientific mystery and technological promise of high temperature superconductivity enables scientific outreach to broad audiences, also supported by this award.