CAREER: Spin-Resolved Imaging of Correlated Electron Systems Including Cuprates and Pnictides

职业：相关电子系统（包括铜酸盐和磷族元素）的自旋分辨成像

• 批准号: 0847433
• 负责人: Jennifer Hoffman
• 金额: $ 52.5万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0847433&HistoricalAwards=false
• 关键词: CAREER; Spin; Resolved; Imaging; Correlated

NON-TECHNICAL ABSTRACTThis CAREER award funds a project to image electron spins in complexmaterials. Although electrons in metals mind their own business, barelyinteracting with each other, in so-called 'strongly correlated electron'materials the interactions of electrons drive unique properties that arefascinating and often useful. For example, so-called high-Tcsuperconductors carry electricity without loss at economically feasibletemperatures; multi-ferroic materials allow electronic data storage usinga magnetic field and magnetic data storage using an electric field; heavyfermion materials boast electrons behaving with thousands of times theiractual mass; simple sheets of carbon called graphene allow electrons tozip along as if they had no mass at all. These materials have in commonthat their electrons interact strongly, and that those interactions arepoorly understood. This project will employ a spin-polarized scanningtunneling microscope to measure the energies and locations of electronspins with atomic resolution, starting with superconductors. The projectwill also use this technology to educate three deserving groups: Harvardstudents will benefit from a new undergraduate course on scanningtunneling microscopy; local elementary school children will be invited tosee a working science lab viewing real electrons; interested citizens willbe able to browse a colorful website explaining the fascinating variety ofmaterials under investigation.TECHNICAL ABSTRACTThis CAREER award funds a project to image electron spins in high-Tcsuperconductors, both cuprates and pnictides. The common feature to theseexotic materials is that their electrons interact strongly, and there isno broadly successful theoretical language to describe these so-called'correlated electron materials'. Great strides have been made throughvarious methods of imaging the interactions of electron charges, butunderstanding has been limited by the lack of effective tools to image theinteractions of electron spins. This project will employ a lowtemperature spin-polarized scanning tunneling microscope to measure thespin-resolved density of electronic states with atomic resolution. Inparticular, a comparison will be made between spin interactions incuprates and pnictides, the only two known families of high-Tcsuperconductors, discovered in 1986 and 2008. The project will also usethis spin imaging technology to educate three deserving groups: Harvardstudents will benefit from a new undergraduate course on scanningtunneling microscopy; local elementary school children will be invited tosee a working science lab imaging real electrons; interested citizens willbe able to browse a colorful website explaining the fascinating variety ofstrongly correlated materials under investigation.

非技术摘要这个职业奖资助一个项目，以图像电子自旋在复杂的材料。 虽然金属中的电子只关心自己的事情，几乎不相互作用，但在所谓的“强相关电子”材料中，电子的相互作用驱动了独特的特性，这些特性令人着迷，而且通常很有用。 例如，所谓的高温超导体在经济上可行的温度下可以无损耗地传输电力;多铁性材料可以利用磁场存储电子数据，利用电场存储磁性数据;重费米子材料拥有数千倍于其实际质量的电子行为;被称为石墨烯的简单碳片可以让电子沿着移动，就好像它们根本没有质量一样。 这些材料的共同点是它们的电子相互作用很强，而人们对这些相互作用知之甚少。 本计画将利用自旋极化扫描隧道显微镜，从超导体开始，以原子级的解析度来量测电子自旋的能量与位置。 该项目还利用这项技术来教育三个值得学习的群体：哈佛大学的学生将受益于一门关于扫描隧道显微镜的新本科课程;当地的小学生将被邀请参观一个正在工作的科学实验室，观察真实的电子;感兴趣的市民可以浏览一个丰富多彩的网站，解释正在调查的各种材料。技术摘要这个职业奖资助一个项目，以成像电子自旋在高温超导体，铜氧化物和磷氧化物。 这些奇异材料的共同特征是它们的电子相互作用很强，并且没有广泛成功的理论语言来描述这些所谓的“相关电子材料”。 通过各种方法来成像电子电荷的相互作用已经取得了很大的进步，但是由于缺乏有效的工具来成像电子自旋的相互作用，理解受到了限制。 本计画将利用低温自旋极化扫描穿隧显微镜，以原子解析度量测自旋分辨电子态密度。 特别是，自旋相互作用之间的比较incuprates和pnictides，只有两个已知的家庭的高Tc超导体，发现于1986年和2008年。 该项目还将利用这种自旋成像技术来教育三个值得关注的群体：哈佛大学的学生将受益于一门关于扫描隧道显微镜的新本科课程;当地的小学生将被邀请参观一个正在工作的科学实验室成像真实的电子;感兴趣的市民将能够浏览一个丰富多彩的网站，解释正在研究的各种强相关材料。