Special Lecture by Prof. Ayan Datta, IACS, Kolkata

Prof. Ayan Datta, IACS, Kolkata, gave a special lecture on 21st April 2022. The title of the presentation was "Pseudo Jahn-Teller Distortions in Two - Dimensional Atomically Thin Monolayers" This lecture was one of the series of events at the Centre for Nano and Soft Matter Sciences (CeNS) to commemorate the 75th anniversary of India's Independence – Aazadi Ka Amrit Mahotsava. He said that Graphene has emerged as one of the most fascinating areas of research in condensed matter and materials science. Apart from graphene, several other 2D analogues like silicene, phosphorene, MXenes, MoS2, germanene have been recently isolated and characterized. One unifying theme among these new materials is that, unlike graphene, they are non-planar. The mode and measure of the buckling (puckering) from planarity depends on the local electronic structure. Pseudo Jahn-Teller (PJT) distortions are shown as a central, unifying concept that explains the overall structural preferences of these systems. The effect of PJT in bestowing structural diversity and novel electronic and spin phases in 2D-monoatomic layers will be discussed in this lecture.