Broadband Infrared Spectrometer

光谱学是实验物理V教授使用的关键实验技术之一，在许多正在进行和计划中的研究项目中都有使用。突出的例子是首次探测到多铁性物质的一般激发，即电子磁振子和磁电自旋波激发，发现反铁磁跃迁中交换诱导声子分裂的普遍性，或者用太赫兹光谱在高磁场中识别贝特弦。然而，目前使用的光谱仪已有20多年的历史，不再符合最先进的红外和太赫兹光谱学。此外，它们变得越来越不可靠，它们的制造商不再提供进一步的服务和维护，它们的计算机控制只能使用过时的系统软件和硬件。因此，可以清楚地预见到这两种设备的产品寿命将很快结束。本提案要求的新型光谱仪大大增强了实验能力，促进了我们小组研究的进一步发展。这对于我们在Transregio TRR80和优先计划SPP 2137范围内使用光谱学进行非常成功的调查至关重要，也是实现提案中描述的各种计划项目的先决条件。特别是，该光谱仪将在研究多铁体和复杂磁体中的磁振子模式，研究多铁体和磁电材料中的动态磁电效应及其相应的光二极管功能，以及观察反铁磁和磁电畴方面发挥重要作用。此外，它还将用于探索量子磁体中的奇异激发，研究非正则铁电体的极性动力学，以及检测自旋-电荷-晶格耦合系统中磁序驱动的结构变化。该装置的进一步应用领域是通过晶格动力学和电子能带结构的变化来研究skyrmiron -host材料（例如，腔隙尖晶石）的结构畸变，检查Dirac材料的拓扑能带结构，以及研究玻璃物质的快速动力学。除了新光谱仪出色的光谱分辨率和带宽外，所有这些研究都将受益于宽带光学微光谱学和新设置中仅包含的拉曼选项。内置超导磁体的光学低温恒温器对于进行磁性化合物的光谱研究至关重要，这是我们感兴趣的重点材料。

Optical spectroscopy is one of the key experimental techniques used in the chair of Experimental Physics V and employed in many ongoing and planned research projects. Prominent examples are the first detection of the generic excitations of multiferroics, namely the electromagnons and the magnetoelectric spin-wave excitations, the discovery of universalities in the exchange-induced phonon splitting at antiferromagnetic transitions, or the identification of Bethe strings by THz spectroscopy in high magnetic fields. However, the currently used spectrometers are more than 20 years old and no longer correspond to the state-of-the-art in infrared and THz spectroscopy. Moreover, they are becoming increasingly unreliable, there is no further service and maintenance provided by their manufacturer, and their computer control is only possible with outdated system software and hardware. Thus a soon end of the product lifetimes of these two devices can be clearly foreseen. The new spectrometer requested in the present proposal has considerably enhanced experimental capabilities, promoting further advances in the research performed by our group. It is essential for the continuation of our very successful investigations using optical spectroscopy, e.g., within the Transregio TRR80 and the Priority Program SPP 2137 and prerequisite for the realization of various planned projects, described in the proposal. Especially, the new spectrometer will play a crucial role in the investigation of magnon modes in multiferroics and complex magnets, for the study of dynamic magnetoelectric effects and the corresponding optical-diode function in multiferroic and magnetoelectric materials, and for the observation of antiferromagnetic and magnetoelectric domains. In addition, it will be applied for the exploration of exotic excitations in quantum magnets, for the study of the polar dynamics in non-canonical ferroelectrics, and for the detection of magnetic-order driven structural changes in spin-charge-lattice coupled systems. Further fields of application of this device are the investigation of structural distortions in skyrmion-host materials (e.g., lacunar spinels) via changes in their lattice dynamics and in their electronic band structure, the examination of the topological band structures in Dirac materials, and the investigation of fast dynamics in glassy matter. Besides the excellent spectral resolution and bandwidth of the new spectrometer, all these studies will profit from the broadband optical micro-spectroscopy and the Raman options only included in the new setup. The optical cryostat with a built-in superconducting magnet will be crucial to perform such spectroscopic studies on magnetic compounds, which are the materials in the focus of our interest.