Ultra-thin layers of semiconductors and their van der Waals heterojunctions are excellent platforms to study exciton and many-body interaction. In this talk, I shall discuss about our recent results on pushing the exciton linewidth and polarization in monolayer semiconductors to the fundamental limits. In particular, I shall show experimental techniques to achieve ~100% valley coherent exciton, and emission linewidth as narrow as what is governed by the limit of the homogeneous broadening. Towards the end, I shall also talk about the dynamic tuning of moiré potential in twisted hetero-bilayers and using Moiré-trapped exciton as a spectroscopic probe.
Prof. Kausik Majumdar is an Associate Professor in the Department of Electrical Communication Engineering, IISc. Bangalore and leads the Quantum Electronics Laboratory. His research activities include using a combination of theoretical and experimental techniques to investigate the electrical and optoelectronic properties of low-dimensional materials and their nanostructures, and exploring their novel device applications.