The Cryogenic Quantum Twisting Microscope, Part II

The discovery of magic angle twisted bilayer graphene has highlighted the fantastic capability to dramatically modify the properties of materials by a small change of their twist angle. To date, however, twisted devices are generally fabricated with a fixed angle that cannot be modified once the device has been made. An in-situ “twistronics” apparatus that can bring into contact two van-der-Waals (vdW) layers and probe the hybrid interface with varying twist angle could be the ideal tool to explore correlated physics in a variety of such interfaces. Recently we have developed the Quantum Twisting Microscope (QTM)¹, capable of performing such in-situ twisting. In the first part of this talk we focused on the momentum-resolving capabilities of this tool, where an insulating barrier between two vdW layers allows one to probe the unperturbed energy-momentum dispersion of the other. In this second part, we will focus on an orthogonal capability of the QTM to perform in-situ “twistronics” experiments. Here, the two vdW layers are brought into direct contact, and the transport properties of the emergent, hybridized interface are measured as the twist angle is continuously scanned. We recently demonstrated a proof-of-principle of this experiment at room temperature. In this talk we will describe the generalization of these experiments into cryogenic temperatures.

[1] Inbar, Alon, John Birkbeck, Jiewen Xiao, Takashi Taniguchi, Kenji Watanabe, Binghai Yan, Yuval Oreg, Ady Stern, Erez Berg, and Shahal Ilani. "The Quantum Twisting Microscope." arXiv preprint arXiv:2208.05492 (2022).