Xiaoqin Elaine Li
University of Texas at Austin – Austin, Texas USA
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Moiré superlattices are typically created by stacking and twisting two functional layers, such as graphene and transition metal dichalcogenides (TMDs). This process often results in simultaneous changes in electronic and photonic properties as a function of the twist angle, which can impose undesirable constraints. An alternative approach involves utilizing the periodic electrostatic potential on the top surface of a twisted hexagonal boron nitride (hBN) substrate to modulate the properties of an adjacent functional layer. This method decouples the generation of the moiré potential from the functional layer, offering significantly greater flexibility in material design.
In this talk, I will discuss our recent studies in engineering the surface potential of twisted hBN substrates. Specifically, I will present our findings on how to confine excitons in a semiconductor monolayer used as the functional layer and how to achieve actively controlled patterned light emission by leveraging the ferroelectric domains formed in the twisted hBN substrate. These results establish twisted hBN as a versatile platform, expanding the scope of moiré engineering to a broad range of functional materials.
Email: elaineli@physics.utexas.edu