Quantum Cafe: Long Ju

Title: Emergent Phenomena in Crystalline Graphene

Abstract: Condensed matter physics has witnessed many emergent quantum phenomena driven by electron correlation and topology. Such phenomena have been mostly observed in conventional crystalline materials where flat electronic bands are available. In recent years, moiré superlattices built upon two-dimensional (2D) materials emerged as a new platform to engineer and study electron correlation and topology. In this talk, I will introduce a family of synthetic quantum materials, based on crystalline multilayer graphene, as a new platform to engineer and study emergent phenomena driven by many-body interactions. This system hosts flat-bands in highly ordered conventional crystalline materials and dresses them with proximity effects enabled by rich structures in 2D van der Waals heterostructures. As a result, a rich spectrum of emergent phenomena including correlated insulators, spin/valley-polarized metals, integer and fractional quantum anomalous Hall effects, as well as superconductivities have been observed in our experiments. I will also discuss the implications of these observations for topological quantum computation.