Physics Department - Scanning Quantum Microscopy for Emergent Phases of Matter

Abstract

Visualization of the nanoscale magnetic response in condensed matter systems offers a powerful approach to unraveling the fundamental mechanisms of spin interactions. Two-dimensional (2D) materials, with their controlled and versatile properties, serve as ideal platforms for exploring exotic correlated and topological states. In the first phase of our study, we achieved a significant breakthrough in investigating twisted double bilayer CrI₃. Our findings reveal a softening of magnetic anisotropy and an indication of magnetic competition at small twisted angles. This competition leads to the emergence of spontaneous periodic skyrmion features with a unique period, distinct from the Moiré periodicity dictated by the twist angle. In the second phase of my research, I focus on 2D superconducting systems, particularly the dynamics of vortices in thin exfoliated 2H-NbSe₂. A key discovery includes the melting of vortex solids near the critical temperature, enabling vortex re-arrangement and resulting in unconventional magnetic noise across different cool-down cycles. These insights open new avenues for understanding and manipulating emergent quantum phenomena in low-dimensional systems.