Low-temperature near-field microscope (LT-SNOM)

该低温近场显微镜可在10 ~ 300开尔文温度范围内记录太赫兹、红外和光学频率范围内的近场光谱，横向分辨率在10 ~ 50 nm之间。这个分辨率明显低于衍射极限，从而允许前所未有的实验进展。为此，除主仪器外，还采用了太赫兹光谱系统、CO2激光源和红外光谱仪。对于红外光谱，我们将额外需要一个红外宽带源，可以从我们并行申请的室温近场显微镜中使用。这一工具的供资可能性是在Weitz教授呼吁访问Göttingen的基本供资框架内获得的，这是建立该小组的一个重要工具。有了显微镜，我们将能够在现代固态研究领域进行各种高度创新的实验。例如，我们将能够在有机电子学领域进行独特的研究。具体来说，我们将首先能够以纳米分辨率局部可视化单个聚合物纤维和低分子薄膜的太赫兹电导率的温度依赖性。这将增加对电荷输运机制理论的重要理解。此外，我们将利用局部红外光谱的独特能力来检测有机半导体的电降解作为温度的函数。利用现有的方法，我们将进一步增加对新型金属有机框架电导率的基本理解。对于范德华材料领域，申请的仪器将非常重要，因为它将允许对例如新型超导相的独特理解。为此，我们将使用横向分辨率低于10nm的红外温度相关局部电导率的横向映射，以潜在地首次检测局部超导相的外观，例如在菱形多层石墨烯中。此外，我们将首先能够追踪双层石墨烯或由新型二维聚合物和石墨烯组成的异质结构中拓扑保护态的温度依赖性。此外，这种独特的仪器将允许对强相关氧化物和电荷密度材料中相变的局部外观作为温度函数的独特见解。

The applied for low-temperature near-field microscope allows to record near-field optical spectra in the range of THz, infrared and optical frequencies in the temperature regime between 10 and 300 Kelvin with a lateral resolution between 10 and 50 nm. This resolution is significantly below the diffraction limit, and thus allows unprecedented experimental progress. To this end additionally to the main instrument, a THz-spectroscopy system, a CO2 laser source as well as an infrared spectrometer are applied for. For the infrared spectroscopy, we will additionally require an infrared broadband source, which can be used from the room-temperature near-field microscope we are applying for in parallel. The funding possibility for this instrument has been granted in the framework of the basic funding for the call of Prof. Weitz to Göttingen, and is an essential tool for the building up of the group. With the microscope, we will be able to perform various highly innovative experiments in the area of modern solid-state research. For example, we will be able to perform unique investigations in the field of organic electronics. Specifically, we will firstly be able to locally visualize the temperature dependence of the THz conductivity of individual polymer fibers and low-molecular films with nm resolution. This will add significant understanding to the theory of charge-transport mechanisms. Additionally, we will use the unique capability of local infrared spectroscopy to detect the electrical degradation of organic semiconductors as function of temperature. With the as-established methods, we will additionally add basic understanding towards the conductivity of novel metalorganic frameworks. For the area of van-der-Waals materials the applied-for instrument will be additionally extremely important, as it will allow unique understanding of e.g. novel superconductive phases. To this end, we will use lateral mapping of the temperature dependent local conductivity in the infrared with a lateral resolution of below 10 nm to potentially firstly detect the appearance of local superconductive phases e.g in rhombohedral multilayer graphene. Additionally we will firstly be able to trace the temperature dependence of topologically protected states in bilayer graphene or in heterostructures composed of novel two-dimensional polymers and graphene. This unique instrument will additionally allow unique insights into the local appearance of phase transitions in strongly-correlated oxides and charge-density materials as function of temperature.