Scanning multi-modality microscopy of moiré quantum matter

Introduction

Moiré materials are a treasure of mind-blowing scope of phenomena, much of which is still to be discovered. Along with the great opportunities, perplexing experimental and theoretical challenges arise due to numerous degrees of freedom, strong interactions, instabilities, broad tunability, and high sensitivity to exact global and local parameters like twist angles, strain, alignment, screening, and disorder.

Challenges

As a result, each moiré device is a mini-universe with its own laws of physics, which cannot be fully unveiled without exploring and cross-correlating a multitude of its microscopic characteristics – an almost formidable task.

Project Goal

The goal of this project is to develop a multi-modality nanoscale scanning probe that can image a wide variety of physical properties with record sensitivity on a single sample, including:

• Currents
• Potentials
• Compressibility
• Magnetization
• Berry curvature
• Topological invariants
• Superfluid density
• Temperature
• Thermal conductivity
• Dissipation
• Work
• Noise

Tool Development

This powerful tool, based on a hybrid superconducting quantum interference device on a tip, will then be applied to study moiré quantum matter over a broad range of variable parameters, including:

1. Temperatures down to mK range
2. Vector magnetic fields
3. Carrier densities
4. Displacement fields
5. Response to local potential perturbations

Research Focus

We will focus on moiré materials beyond the magic-angle twisted bilayer graphene, including multilayer and hybrid twisted van der Waals structures, which offer a fertile platform for realizing novel states of matter.

Key Questions

We will address key open questions and provide nanoscale visualization and comprehension of the mechanisms governing:

• Topology
• Berry curvature
• Orbital magnetism
• Superconducting order parameter
• Topological magnetic textures
• Heat and charge transport
• Dissipation
• Noise

Conclusion

This research will provide groundbreaking insight into the complexity and the beauty of the emergent multi-facet physics flourishing in moiré materials.