SOLSTICE - SOLids in Strong Terahertz and Infrared CE-phase-stable waveforms

在凝聚态物质和纳米系统中发生的亚光周期时间尺度上的光波驱动电子动力学是最初在原子和分子中研究的阿秒科学的一个迷人的前沿。调整阿秒计量技术来观察和控制大量已知固体和新型量子材料中最快的电子动力学，这对丰富的基础科学发现具有很大的希望，从而可能影响未来的技术，例如新兴的拍赫兹电子信号处理或强场光电子学。在SOLSTICE项目的第二个资助期，我们希望继续我们正在进行的研究，调查固体辐射的强太赫兹（太赫兹）和定制的红外（IR）载波包络相位（CEP）稳定的光学波形。特别是，研究高次谐波产生（HHG），这是阿秒科学的基石之一，在这里作为一个非微扰强场过程的范例，我们要更深入地阐明物理相似性和差异相比，在原子和分子气体中的相应过程。最重要的是，我们希望探索定制的强IR-THz场和次级阿秒HHG源为高级光谱应用所带来的前所未有的能力。在这个联合实验/理论项目中，通过将HHG实验与从头算含时密度泛函理论（TDDFT）模拟相结合，我们希望将HHG从半导体和绝缘体扩展到更复杂的固体，包括二维（2D）材料，强相关材料和拓扑绝缘体。因此，该项目有望在结合强场attoscience和Mott-Hubbard物理学方面开辟新天地。偏振态分辨的高次谐波光谱对亚周期电子和结构动力学敏感，将为量子材料的超快光谱研究开辟新的途径。我们将从二维材料中合成类似原子的HHG的“完美波形”，并将其与气相对应物进行比较。我们还希望探索新的机会，太赫兹敷料为基础的对称性控制表现在高次谐波从晶体。此外，利用孤立的阿秒XUV脉冲和子周期光学波形的时间分辨光谱学，可以研究具有强激子效应的材料（如二维材料）的动力学。除了解决本项目中的基本物理问题外，我们的研究工作还旨在突破目前固体高次谐波的技术限制，实现明亮、紧凑的固态阿秒XUV光源和真空紫外/用于未来光谱学的XUV频率梳。

Lightwave-driven electronic dynamics occurring on sub-optical-cycle time scales in condensed-matter and nanosystems is a fascinating frontier of attosecond science originally studied in atoms and molecules. Adapting attosecond metrology techniques to observe and control the fastest electronic dynamics in the plethora of known solids and novel quantum materials holds great promise for a wealth of fundamental scientific discoveries, thereby potentially impacting future technologies such as emerging petahertz electronic signal processing or strong-field optoelectronics.In the second funding period of the SOLSTICE project, we want to continue our ongoing research investigating solids irradiated by strong terahertz (THz) and tailored infrared (IR) carrier-envelope phase (CEP)-stable optical waveforms. In particular, studying high-harmonic generation (HHG), which is one of the cornerstones of attosecond science serving here as paradigm of a nonperturbative strong-field process, we want to elucidate in greater depth the physical similarities and differences compared to the corresponding process in atomic and molecular gases. Most importantly, we want to explore the unprecedented capabilities emerging from tailored intense IR-THz fields and secondary attosecond HHG sources for advanced spectroscopic applications.In this joint experiment/theory project, by combining HHG experiments with ab-initio time-dependent density-functional theory (TDDFT) simulations, we want to extend HHG from semiconductors and insulators to more complex solids including two-dimensional (2D) materials, strongly correlated materials, and topological insulators. This project is thus expected to break new ground in combining strong-field attoscience and Mott-Hubbard physics. Polarization-state-resolved high-harmonic spectroscopy sensitive to sub-cycle electronic and structural dynamics will open up new avenues in ultra-fast spectroscopy of quantum materials. We will synthesize "perfect waveforms" for atomic-like HHG from 2D materials and compare it to the gas-phase counterpart. We also want to explore new opportunities of THz-dressing-based symmetry control manifesting in HHG from crystals. Furthermore, time-resolved spectroscopy with isolated attosecond XUV pulses and sub-cycle optical waveforms permits to study dynamics in materials featuring strong excitonic effects such as 2D materials.Beside tackling fundamental physical questions in this project, our research efforts also aim to push the present technological limitations of solid-HHG to realize bright and compact solid-state attosecond XUV sources and VUV/XUV frequency combs for future spectroscopies.