论文标题
量子扭曲显微镜
The Quantum Twisting Microscope
论文作者
论文摘要
扫描探针显微镜的发明彻底改变了电子现象的可视化方式。虽然当今的探针可以在空间中的单个位置访问各种电子特性，但可以直接探测电子在多个位置的量子机械存在的扫描显微镜将直接访问电子系统的关键量子特性，因此无法实现。在这里，我们演示了一种概念上的新型扫描探针显微镜 - 量子扭曲显微镜（QTM） - 能够在其尖端执行局部干扰实验。 QTM基于独特的Van-Waals尖端，允许创建原始的2D连接，该连接为电子提供了多种相干切断的路径，可以将电子隧道隧穿到样品中。通过在尖端和样品之间添加连续扫描的扭角，该显微镜在动量空间中探测电子，类似于扫描隧道显微镜在真实空间中探测电子的方式。通过一系列实验，我们在尖端展示了室温量子相干性，研究扭曲的双层石墨烯的扭角演化，直接对单层和扭曲的双层石墨烯的能带直接成像，最后施加巨大的局部压力，同时可视化后者平坦能带的演化。 QTM为量子材料的新型实验开辟了道路。
The invention of scanning probe microscopy has revolutionized the way electronic phenomena are visualized. While present-day probes can access a variety of electronic properties at a single location in space, a scanning microscope that can directly probe the quantum mechanical existence of an electron at multiple locations would provide direct access to key quantum properties of electronic systems, so far unreachable. Here, we demonstrate a conceptually new type of scanning probe microscope - the Quantum Twisting Microscope (QTM) - capable of performing local interference experiments at its tip. The QTM is based on a unique van-der-Waals tip, allowing the creation of pristine 2D junctions, which provide a multitude of coherently-interfering paths for an electron to tunnel into a sample. With the addition of a continuously scanned twist angle between the tip and sample, this microscope probes electrons in momentum space similar to the way a scanning tunneling microscope probes electrons in real space. Through a series of experiments, we demonstrate room temperature quantum coherence at the tip, study the twist angle evolution of twisted bilayer graphene, directly image the energy bands of monolayer and twisted bilayer graphene, and finally, apply large local pressures while visualizing the evolution of the flat energy bands of the latter. The QTM opens the way for novel classes of experiments on quantum materials.
