Substrate-supported atomic-scale In nanowires:Structure, phase transition and spectroscopic properties

拟议的理论-实验联合项目旨在从光谱特征中提取对Si(111)上纳米线中的原型的更深层次的理解。除了基态结构外，还将通过非接触表面光学光谱和基于密度泛函理论(DFT)的第一性原理计算相结合来探讨吸附原子和缺陷对金属-绝缘体相变的影响。利用远红外(FIR)光学光谱和拉曼光谱，我们测量了由带间和带内跃迁以及表面振动引起的电子激发。将测量的光谱指纹与计算的特征进行比较，可以探索候选结构，并有望彻底理解纳米线几何形状和电子性质之间的关系。此外，这些计算将有助于使温度诱导相变的能量学和驱动力合理化，并将用于将纳米线的朗道电导与其结构性质和外部修饰联系起来。

The proposed joint theoretical-experimental project aims to extract a deeper understanding of the prototypical In nanowires on Si(111) from spectroscopic signatures. In addition to the ground-state structure, the impact of adatoms and defects on the metal-insulator phase transition will be explored by combining non-contact surface optical spectroscopy with first-principles calculations based on density-functional theory (DFT). With optical spectroscopy into the far infrared (FIR) as well as Raman spectropscopy we measure electronic excitations due to inter- and intraband transitions as well as surface vibrations. The comparison of the measured spectroscopic fingerprints with calculated signatures allows for probing structural candidates and is expected to lead to a thorough understanding of the relation between the nanowire geometry and electronic properties. Furthermore, the calculations will help to rationalise the energetics and driving forces of the temperatureinduced phase transition and will be used to relate the Landauer conductance of the nanowires to their structural properties and external modifications.