Strain-tuning electronic structure and quantum many-body interactions

量子材料代表着一项前沿研究努力。它们奇异物理性质核心的强烈相互作用使理解它们的材料性质成为现代固体物理和材料化学最深刻的挑战之一，更不用说预测了。然而，这个问题不仅仅是智力上的好奇；利用对这些系统可以承载的集体状态的控制，如超导、金属-绝缘体转变和磁性有序，可能会为设计快速、节能和智能的多功能技术开辟新的途径，使用与当今基于硅的逻辑完全不同的设计原则。为了改善对这些系统的基本理解，从而最终利用这些系统，需要有控制的、新的、实验性的方法。在这里，我们建议开发新的能力，以施加大的，可逆的，连续可调的单轴压力与角度分辨光电子发射实验相结合。这为量子材料的电子结构和多体相互作用的演化提供了新的见解，当受到一个特别干净的调谐参数时，这对于我们进一步理解固体中的量子多体问题是至关重要的。为此，我们将重点研究两个关键的材料体系，金属过渡金属二卤化物和层状Ruthenate氧化物。作为潜在的拓扑激发宿主，作为新的2D材料候选者，以及作为非传统磁体，它们各自都具有巨大的电流兴趣，在这里选择它们是为了提供对固体中相竞争、电子-晶格相互作用和强电子关联的本质的重要补充见解。

Quantum Materials represent a frontier research endeavour. The strong interactions at the heart of their exotic physical properties has made understanding, let alone predicting, their materials properties one of the most profound challenges of modern-day solid state physics and materials chemistry. This problem is not just an intellectual curiosity, however; harnessing control over the collective states that these systems can host, such as superconductivity, metal-insulator transitions, and magnetic orderings, could open new routes to designing fast, energy-efficient, and smart multifunctional technologies, operating using completely different design principles to the Silicon-based logic of today. To progress towards an improved fundamental understanding, and thereby ultimate exploitation, of these systems requires controlled, new, experimental approaches. Here, we propose to develop new capabilities for applying large, reversible, and continuously-tuneable uniaxial pressures in conjunction with angle-resolved photoemission experiments. This promises novel insight into how the electronic structures and many-body interactions of quantum materials evolve when subjected to a particularly clean tuning parameter, which is of fundamental importance to further our understanding of the quantum many-body problem in solids. To this end, we will focus on two key materials systems, the metallic transition-metal dichalcogenides and the layered ruthenate oxides. These are each of enormous current interest in their own right, as potential hosts of topological excitations, as new 2D materials candidates, and as unconventional magnets, and are chosen here to provide important complementary insights into the nature of phase competition, electron-lattice interactions, and strong electronic correlations in solids.