Time-resolved spectroscopy of photo-induced transitions and electronic excitations in quasi-1D metal wires on semiconductors

半导体上准一维金属线中光致跃迁和电子激发的时间分辨光谱

• 批准号: 221711595
• 负责人: Professor Dr. Uwe Bovensiepen
• 金额: --
• 依托单位: Fraunhofer-Institut für Mikroelektronische Schaltungen und Systeme (IMS)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/221711595?language=en
• 关键词: Time; resolved; spectroscopy; photo; induced

The project E5 aims at a fundamental understanding of the non-equilibrium properties of quasi-1D metal wires on semiconductor surfaces and focuses on the ultrafast dynamics of electronic excitations, including spectroscopy and lifetimes of unoccupied electronic states as well as on transient changes of the electronic band structure during photoinduced phase transitions in such systems. These topics will be addressed using In/Si(111), Pb/Si(557), and Au/Si(553) as model systems. The activities located in Duisburg and Berlin share joint scientific goals, but use different experimental approaches: The group at the University of Duisburg-Essen focuses on the spectroscopy and dynamics of unoccupied electronic states near the center of the Brillouin zone using time- and angle-resolved photoemission (ARPES) and two-photon photoemission (2PPE) spectroscopy. The group at the Fritz Haber Institute in Berlin develops time-resolved XUV-based ARPES to study electron dynamics and electronic structure changes during photoinduced phase transitions throughout the complete Brillouin zone. The latter experiments will be complemented by time-resolved optical spectroscopy (SFG, RAS) in the regime of high laser fluence building on experiments with static optical spectroscopy (RAS) performed in E3. The ultrafast techniques employed in our project investigate the excited state electron dynamics. Within the Research Unit our activity forms together with projects T1 and T2, which theoretically treat changes in the electronic structure upon CDW formation and photo-induced phase transitions, and with project E7, which analyzes the complementary structural dynamics by femtosecond electron diffraction, a focus area on dynamics in 1D systems.

E5项目旨在对半导体表面上的准一维金属线的非平衡特性有一个基本的了解，并重点研究电子激发的超快动力学，包括光谱学和未占据电子态的寿命，以及在这些系统的光诱导相变过程中电子能带结构的瞬态变化。这些主题将使用In/Si（111）、Pb/Si（557）和Au/Si（553）作为模型体系来讨论。位于杜伊斯堡和柏林的活动具有共同的科学目标，但使用不同的实验方法：杜伊斯堡-埃森大学的研究小组使用时间和角度分辨光发射（ARPES）和双光子光发射（2PPE）光谱，专注于布里温区中心附近的未占据电子态的光谱和动力学。柏林Fritz Haber研究所的研究小组开发了基于时间分辨率xuv的ARPES，用于研究整个布里渊区光诱导相变期间的电子动力学和电子结构变化。后一项实验将在E3进行的静态光谱学（RAS）实验的基础上，在高激光通量下进行时间分辨光谱学（SFG， RAS）的补充。在我们的项目中使用的超快技术研究激发态电子动力学。在研究单位，我们的活动与项目T1和T2一起形成，项目T1和T2从理论上研究CDW形成和光诱导相变时电子结构的变化，以及项目E7，项目E7通过飞秒电子衍射分析互补结构动力学，这是一维系统动力学的一个重点领域。