Cory Dean1
Columbia University1
Twisted and/or lattice mismatched van der Waals heterostructures have emerged as a kind of universal platform, capable of manifesting a wide range of electronic and optical properties spanning metallic, insulating, semiconducting, semimetal, magnetic, superconducting, and topological behaviours. Perhaps most remarkable is the opportunity to transform between these states within a single material platform - an exciting new degree of freedom that has been termed, twistronics. So far the vast majority of studies have reported static devices, where the moire pattern in a heterostructure is established by the lattice alignment during the fabrication process such that each device represents a single twist angle. However the weak interlayer bonding between van der Waals materials means that it is possible to realize devices where the twist angle can be dynamically varied post-fabrication. Here I will discuss our ongoing efforts to develop improved in-situ control with the goal towards realizing fully in-situ tunable devices structures. I will discuss recent progress in terms of mechanical rotation of individual monolayers, improved understanding of interfacial dissipation mechanisms, implementation of in-situ feedback of twist angle and new approaches towards developing non-mechanical control of the heterostructure geometry at the nanoscale. Prospects for realizing functional twistronic devices with real-time in-situ control will be discussed.