International Research Fellowship Program: Infrared and Optical Studies of Quantum Phase Transitions

国际研究奖学金计划：量子相变的红外和光学研究

• 批准号: 0402699
• 负责人: Norman Armitage
• 金额: $ 7.9万
• 依托单位: Armitage Norman P
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2005-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0402699&HistoricalAwards=false
• 关键词: International; Research; Fellowship; Program; Infrared

0402699ArmitageThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a sixteen-month research fellowship by Dr. Norman P. Armitage to work with Dr. Dirk van der Marle at the University of Geneva in Switzerland. This project concerns the study of optical and infrared properties of condensed matter systems near so-called quantum phase transition (QPTs). This a topic at the forefront of some of the most challenging and interesting problems in condensed matter physics. Once thought to be a theoretical curiosity, it is becoming increasingly clear that the existence of nearby QPTs may hold the key to understanding the unusual behavior of many systems at the forefront of condensed matter physics. The optical and infrared response of correlated electron systems, such as superconductors and novel magnetic states, are being investigated as they are tuned via an external parameter (e.g. pressure, carrier density, or magnetic field) through such a transition between various magnetic and superconducting ground states near absolute zero temperature. The work is being done in the group of Prof. Dirk van der Marel at the University of Geneva using both the state-of-the-art facilities of Dr. van der Marel's lab and new infrared systems being currently installed at the Swiss Light Source (SLS) synchrotron. Prof. van der Marel's present work concentrates on the low energy excitation spectra of strongly correlated electron systems, using various infrared and optical spectroscopic probes. The lab in Geneva is uniquely equipped for this project as one of the top laboratories in the world for such investigations. However, the optical study of pressure-tuned QPTs (such as those found in heavy fermion systems), necessitates the use of small beam spots for coupling into a diamond anvil pressure cells. This is a requirement incompatible with traditional lab based infrared or optical sources, but made possible by the advent of infrared synchrotron radiation (IRSR) sources. One of the unique aspects of this project is the use of newly commissioned infrared beamlines at the SLS.

0402699Armitage国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。 该项目的奖项为联合研究以及使用国外独特或互补的设施、专业知识和实验条件提供了机会。该奖项将支持 Norman P. Armitage 博士与 Dirk van der Marle 博士合作为期 16 个月的研究奖学金在瑞士日内瓦大学。该项目涉及研究所谓量子相变（QPT）附近的凝聚态物质系统的光学和红外特性。 这是凝聚态物理中一些最具挑战性和有趣问题的前沿主题。 曾经被认为是一种理论上的好奇心，现在越来越清楚的是，附近 QPT 的存在可能是理解凝聚态物理前沿许多系统的异常行为的关键。 相关电子系统（例如超导体和新型磁态）的光学和红外响应正在研究中，因为它们通过外部参数（例如压力、载流子密度或磁场）通过各种磁性和超导地之间的转变进行调整接近绝对零温度的状态。 这项工作由日内瓦大学的 Dirk van der Marel 教授小组完成，使用了 van der Marel 博士实验室最先进的设施和瑞士光源目前安装的新型红外系统（SLS）同步加速器。 van der Marel 教授目前的工作重点是使用各种红外和光学光谱探针研究强相关电子系统的低能激发光谱。 日内瓦实验室为该项目配备了独特的设备，是世界上进行此类研究的顶级实验室之一。 然而，压力调谐 QPT（例如重费米子系统中发现的 QPT）的光学研究需要使用小束斑耦合到金刚石砧压力单元。 这一要求与传统实验室红外或光源不兼容，但由于红外同步加速器辐射 (IRSR) 源的出现而成为可能。 该项目的独特之处之一是在 SLS 中使用新调试的红外光束线。