Title : Bottom-up engineering of new electronic and structural effects with atomic layers.
Speaker : Prof. Arindam Ghosh, IISc Bangalore.
Date : 07/04/2021, 05:30 PM , Online Mode.
Van der Waals heterostructures represent a new paradigm of material design, where two atomic or molecular planes of different chemical origin are brought together within the sub-nanometer van der Waals distance. When two atomic layers are placed so close their electronic states may hybridize, and the physical properties are modified by the rules of momentum conservation and structural commensurability. In this talk I shall present several new physical phenomena, in multiple domains ranging from electronic, opto-electronic to thermoelectric properties, that emerge as a result of van der Waals heterostructuring of two-dimensional (2D) materials. Apart from achieving high carrier mobility and ultra-low noise in electrical transport, encapsulating graphene by boron nitride leads to manifestation of edge transport and trigonal warping at low energies. Optoelectronic properties are strongly enhanced on graphene and transition metal dichalcogenide heterostructures, that can be extended to single photon detection. I shall also show new phenomena in thermoelectric transport in twisted bilayer graphene, where the Seebeck coefficient is strongly determined by the angular misorientation between the graphene layers in the van der Waals stack.
About the speaker:
Arindam Ghosh is a renowned experimental condensed matter physicist and a professor in the Department of Physics at the Indian Institute of Science, Bangalore, India. He is the recipient of the Shanti Swarup Bhatnagar Prize for science and technology, the highest science award in India. In 2020, he was awarded the Infosys Prize for Physical Science, one of the most prestigious awards that recognizes achievements in science and research in India. Prof. Ghosh did his bachelors from Calcutta University, and his masters and PhD from IISc, Bangalore. He then joined as a postdoctoral research associate at the University of Cambridge, UK before joining IISc as an assistant professor in 2005. His current research interests include the transport properties of two-dimensional electronic systems in semiconductors, carbon-based low-dimensional systems, optoelectronic properties of atomically-thin semiconductor membranes, magnetic nanostructures, and structural stability of nanoscale systems such as metallic nanowires and nanoparticles.