Thursday Colloquium Series
Twistronics: A Recent Avenue in van der Waals Heterostructures
The inaugural seminar of the Thursday Colloquium Series organized by the Department of Physics, IIT Bhilai was held on September 24, 2020. Dr. Pramoda Kumar Nayak, an expert on two dimensional (2D) material from IIT Madras, spoke on “Twistronics: A Recent Avenue in van der Waals Heterostructures”.
During the seminar, Dr. Nayak discussed that after the discovery of graphene, the most prominent representative class of two-dimensional (2D) layered materials, many other 2D crystals have been identified, often with intriguing properties that have no counterparts in three-dimensional solids. Such 2D materials own various interesting and unexpected properties; for instance, 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 crystal 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.
In this talk, Dr Nayak covered the atlas of vdW materials and their heterostructures emphasizing on synthesis, characterization and potential applications in electronics and optoelectronics. Additionally, he described how a simple twist can dramatically change the functionalities of vdW HSs, fabricated from 2D monolayers grown by chemical vapor deposition. To conclude, he summarized the current challenges and future opportunities that are available in this emerging field.