2D and Moiré Materials | Strong Correlations and Topology | Quantum Transport and Surface Probes

Quantum transport at extreme conditions

While room-temperature electrical phenomena are most desired for application potentials, many novel and exotic phases of matter appear only at extremely low temperatures and high magnetic fields. Our work makes use of cryogen systems, to study the electrical and magnetic properties of quantum materials at temperature just a few 10ths of a degree above absolute zero (about -459.65 Fahrenheit) and high magnetic fields (~1000x your standard refrigerator magnet).

Moiré patterns give rise to unique quantum transport signatures such as the “fan” diagrams shown above. The “quantum oscillations” in this image give us information about the physics and topology of the system being studied.

Surface Probe Measurements

2D materials are particularly ammenable to study and manipulation using surface probe techniques, where a sharp tip is brought nearby or into contact with an exposed surface. The tip can then be rastered over the sample surface with piezoelectronics and feedback controls to image the surface. The Waters Lab frequently uses various atomic force microscopy (AFM) techniques, like tapping mode, contact mode, Kelvin probe, piezo-force, and anodic nanolithography. We also have expertise in scanning tunneling microscopy (STM), a remarkable technique that can visualize individual atoms! Above is an STM image, where we can resolve individual atoms (the small dots) and a longer wavelength moiré pattern created by a misalignment of the top and bottom atomic layers.