Yankowitz, MatthewThompson, Ellis2026-02-052026-02-052026-02-052025Thompson_washington_0250E_29053.pdfhttps://hdl.handle.net/1773/55290Thesis (Ph.D.)--University of Washington, 2025Since the discovery of monolayer graphene in 2004, van der Waals (vdW) materials have become a mainstay in condensed matter physics. Their layered nature enables us to isolate atomically thin sheets and stack them together with virtually limitless possibility. These designer 2D heterostructures also introduce a new twisting degree of freedom, in which layers are stacked with a rotational offset. The beating pattern formed between their crystalline lattices is known as a moiré superlattice and often leads to new and unexpected properties absent in the parent materials. In this dissertation, I will push the boundaries of this ever-growing parameter space through electronic characterization of various novel moiré materials. The prototypical example of a moiré heterostructure consists of two graphene layers stacked with a small interlayer twist and has been shown to exhibit a wide variety of novel electronic properties driven by strong electron-electron interactions. In the first part of this thesis, we show that adding more layers to this basic framework preserves much of the same physics and in some cases leads to entirely new electronic phenomena. Furthermore, we find that signatures of the moiré superlattice survive into bulk graphite structures, composed of up to ~40 layers of graphene. The second part of this thesis focuses on moiré systems composed of transition metal dichalcogenides, a class of vdW materials composed of alternating layers of transition metal and chalcogen atoms. In particular, twisted molybdenum ditelluride (tMoTe2) was recently found to exhibit the long-sought fractional quantum anomalous Hall (FQAH) effect, a consequence of strong electron interactions and robust band topology. We use scanning tunneling microscopy to image the energy-dependent nanoscale wave function of tMoTe2, illustrating a connection between its microscopic structural properties and band topology.application/pdfen-USnoneCondensed matter physicsMaterials SciencePhysicsThesis