Abstract:
Some of the most fascinating phenomena in nature emerge when electrons
behave as quantum mechanical waves, interacting with each other in complex
ways. But how can we visualize these electronic waves in action? In this talk, I
will introduce the Quantum Twisting Microscope 1 (QTM), an innovative
scanning probe microscope, designed for imaging electronic waves in quantum
materials. At its core lies a unique tip composed of an atomically thin van der
Waals material. When this tip is brought into contact with another quantum
material, it forms a pristine two-dimensional interface that can be twisted with
precision. A single electron tunnels across this interface at multiple points at
once, and the quantum interference between these tunneling events turns the tip
into a highly sensitive interferometer that probes electrons in momentum space. I
will discuss recent experiments visualizing electron and phonon dispersions in
twisted bilayer graphene, uncovering surprisingly strong interactions 2 .
Additionally, I will present experiments utilizing a single atomic defect, within
the QTM interface, as a scanning single-electron-transistor, producing ultra-
high-resolution images of the potential landscapes experienced by electrons
within moiré lattices.
[1] The Quantum Twisting Microscope, A. Inbar, et al., Nature 614, 682-687 (2023).
[2] Measuring Phonon Dispersion and Electron-Phason Coupling in Twisted Bilayer Graphene with a
Cryogenic Quantum Twisting Microscope, J. Birkbeck et al., arXiv:2407.13404 (2024).
[3] Imaging the Sub-Moiré Potential Landscape using an Atomic Single Electron Transistor, D. Klein,
et al., arXiv:2410.22277 (2024).