Twistronics : A recent average in Van der Waals heterostructures

The lecture on "Twistronics : A recent average in Van der Waals heterostructures" by Pramoda Kumar Nayak was held on 21, Jun 2021. He explained about the discovery of graphene in 2004, many other 2D crystals have been identified, often with intriguing properties that have no counterparts in three-dimensional solids. Even if individual 2D materials own various interesting and unexpected properties, the stacking of such layers leads to 'artificial vdW solids' called as van der Waals heterostructures (vdW HSs) that result in the emergence of new states of matter with novel functionalities. The vdW HSs not only depend on the combination of different 2D crystals but also on their rotational alignment opening the avenue for a new field called twistronics. Coupling between the two layers depends on the stacking angle, which can be used as an external degree of freedom to tune their optical and electronic properties. The speaker covered the atlas of vdW materials and their heterostructures emphasizing on synthesis, characterization and potential applications in electronics and optoelectronics. He described how a simple twist can dramatically change the functionalities of vdW HSs, fabricated from 2D monolayers grown by chemical vapor deposition. He also summarized the current challenges and future opportunities in this emerging field.