Bottom-up engineering of new electronic and structural effects with atomic layers
ABSTRACT :
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 Professor of Physics at the Indian Institute of Science in Bangalore, India. His research interest involves fundamental understanding of physics and device concepts in multiple two-dimensional (2D) electron systems, with emphasis on transport, optical and thermal properties of layered membranes. The work of his group led to new discoveries in ultra-sensitive optical detection, tunable thermoelectric designs, and power efficient memo ry devices for neuromorphic applications. Prof. Ghosh’s group was among the first to demonstrate strong light-matter interaction in binary heterostructures of graphene and transition metal dichalcogenides, and also measure electrical noise in atomically thin two-dimensional systems. Prof. Ghosh has guided nearly twenty PhD students so far, and serves on the Editorial/Advisory board of several international journals from Springer, IoP and ACS and conferences. He is a regular reviewer for multiple publishing outlets including the Nature Publishing Group, American Physical and Chemical Societies, and IoP publishing. He has been the recipient of several recognitions and fellowships including the Swarnajayanti Fellowship, IBM-IUSSTF (Indo-US Science and Technology Forum) fellowship in Nanotechnology, the Shanti Swarup Bhatnagar Prize, Oxford Instruments Young NanoScientist Award, P.K. Aiyenger Memorial Award and the J. C. Bose National fellowship.