Science Daily February 23, 2023
An international team of researchers (Israel, Japan) developed and demonstrated conceptually, a new type of tool — the quantum twisting microscope (QTM) — that could create novel quantum materials while simultaneously gazing into the most fundamental quantum nature of their electrons. It is 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 two-dimensional 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 along a line in momentum space similar to how a scanning tunnelling microscope probes electrons along a line in real space. Through a series of experiments, they demonstrated room-temperature quantum coherence at the tip, studied the twist angle evolution of twisted bilayer graphene, directly imaged the energy bands of monolayer and twisted bilayer graphene and, finally, applied large local pressures while visualizing the gradual flattening of the low-energy band of twisted bilayer graphene. The QTM opens the way for new classes of experiments on quantum materials. The study’s findings may be used to create electronic materials with unprecedented functionalities… read more. TECHNICAL ARTICLEÂ
Momentum-resolved tunnelling between two twisted graphene monolayers. Credit: Nature volume 614, pages682–687 (2023)