time-resolved μARPES and TOF-PEEM setup (Teilfinanzierung)

提出了一种真实的空间“μm”视场的时间和角度分辨光电子能谱（tr-μARPES）和时间分辨光电子能谱电子显微镜（tr-PEEM）的装置。该装置将包括一个100 kHz的激光放大器，一个用于有效产生中红外泵浦脉冲的具有差频产生（DFG）的光学参量放大器（OPA），一个用于产生（极）紫外探测脉冲的源，一个配备飞行时间光电发射电子显微镜的TOF-PEEM室在一个实施例中，显微镜系统包括一个光学显微镜（也称为飞行时间动量显微镜）、一个氦冷却样品显微镜载物台、一个样品制备室和一个装载锁。这种设置将使我们能够测量非平衡载流子动力学在真实的和倒易空间和瞬态带结构的各种低维固体和二维异质结构暴露于可见光，红外，以及强场MIR泵浦脉冲。与更传统的半球形分析仪相比，设想的TOF-PEEM提供了重要的优势，包括（1）在真实的和倒易空间中拍摄图像的可能性，其中整个光电发射视界可以在单次拍摄中访问，以及（2）在μARPES模式下减小TOF-PEEM的视场的可能性，这将允许我们测量小的或不均匀的样品的能带结构。100 kHz的重复率将确保合理的积分时间的出色信噪比，并减轻空间电荷问题。低温将允许我们进入各种不同的破缺基态。该装置将被用来研究扭曲的货车德瓦尔斯异质结构中的载流子动力学，以及不同的低维固体暴露于准周期MIR驱动的瞬态能带结构。

We propose a setup for time- and angle-resolved photoemission spectroscopy with "μm" -sized field of view in real space (tr-μARPES) and time-resolved photoemission electron microscopy (tr-PEEM). The setup will include a 100kHz laser amplifier, an optical parametric amplifier (OPA) with difference frequency generation (DFG) for the efficient generation of mid-infrared pump pulses, a source for the generation of (extreme) ultraviolet probe pulses, a TOF-PEEM chamber equipped with a time-of-flight photoemission electron microscope (also referred to as time-of-flight momentum microscope), a Helium-cooled sample microscopy stage, a sample preparation chamber, and a load lock. This setup will allow us to measure the non-equilibrium carrier dynamics both in real and reciprocal space and the transient band structure of various low-dimensional solids and two-dimensional heterostructures exposed to visible, infrared, as well as strong-field MIR pump pulses. The envisioned TOF-PEEM offers important advantages compared to more conventional hemispherical analyzers including (1) the possibility to take images both in real and reciprocal space where the whole photoemission horizon can be accessed in a single shot, and (2) the possibility to reduce the field of view of the TOF-PEEM in μARPES mode which will allow us to measure the band structure of small or inhomogeneous samples. The repetition rate of 100kHz will ensure excellent signal-to-noise ratios for reasonable integration times and mitigate space charge issues. Cryogenic temperature will allow us to access various symmetry-broken ground states. The setup will be used to investigate carrier dynamics in twisted van der Waals heterostructures as well as the transient band structure of different low-dimensional solids exposed to quasi-periodic MIR driving.