Momentum-dependent electron dynamics in a 2D aperiodic potential

二维非周期势中动量相关的电子动力学

• 批准号: 528316563
• 负责人: Professor Dr. Wolf Widdra
• 金额: --
• 依托单位: National Science and Technology Council (NSTC)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/528316563?language=en
• 关键词: Momentum; dependent; electron; dynamics; 2D

The field of electronic structure and electron dynamics of long-range ordered aperiodic systems is still in its infancy. In strong contrast to the well-studied electron dynamics in 2D and 3D periodic crystals, the absence of translational symmetry within the aperiodic potentials of quasicrystals is incompatible to the traditional picture of band structure and the delocalized Bloch states. In this context, our Taiwan-German project focusses on electrons in image potential states at the surface of dodecagonal oxide quasicrystals. It combines the advancement of 2D quasicrystal growth and the time- and momentum-resolved two-photon photoelectron spectroscopy. For dodecagonal oxide quasicrystals derived from BaTiO3 and SrTiO3 thin films grown on metallic substrates, image potential states are ideally accessible. For this textbook electron system, the impact of the aperiodic 2D structure on the energy-momentum dispersion of electrons and their femtosecond dynamics will be studied. Results for aperiodic potentials of different fundamental length and strength allow for a systematic comparison of induced modifications.

长程有序非周期系统的电子结构和电子动力学领域仍处于起步阶段。与 2D 和 3D 周期性晶体中经过充分研究的电子动力学形成鲜明对比的是，准晶体的非周期性势内缺乏平移对称性，这与能带结构和离域布洛赫态的传统图像不相容。在这种背景下，我们的台湾-德国项目重点研究十二方氧化物准晶体表面图像势态的电子。它结合了二维准晶体生长和时间和动量分辨双光子光电子能谱的进步。对于在金属基底上生长的 BaTiO3 和 SrTiO3 薄膜衍生的十二角氧化物准晶体，理想情况下可以获得图像势态。对于这本教科书电子系统，将研究非周期二维结构对电子能量动量色散及其飞秒动力学的影响。不同基本长度和强度的非周期势的结果允许对诱导修饰进行系统比较。