Yashonath Subramanian did his five year integrated M.Sc.(Hons) from BITS, Pilani in 1974. He earned his Ph.D. degree from IISc, Bangalore (1979) working under the supervision of Professor C.N.R. Rao. Subsequently, he was a Post-doctoral research associate in the Department of Chemistry at University of Cambridge, United Kingdom and Davy Faraday Research Laboratoy, Royal Institution of Great Britain, United Kingdom, (1985-1987) and Department of Chemistry, University of Pennsylvania, Philadelphia, USA. He joined as a Lecturer in Solid State and Structural Chemistry Department, Indian Institute of Science. He has been a visiting professor at Department of Chemistry, University of Sassari, Italy in 2008 and 2011. He is currently a professor at IISc.
Academic and Research Achievements: Yashonath's research interest is in the area of theoretical chemistry : new computational techniques, phase transformations in solids, diffusion and its variation with radius of the diffusant, pressure, density, etc in different condensed matter phases. An improved method to prevent rotations in the Parrinello-Rahman variable shape method for study of phase transformations is presently used internationally. Among his significant contributions are the discovery of anomalous dependence of diffusivity on radius of the diffusant known as the Levitation Effect. This effect is a universal phenomenon observed in all condensed matter phases. This finding suggests a breakdown in Stokes-Einstein relationship for small solute sizes and has been able to account for enhanced diffusivity reported by several groups. It has also been able to account for the different trends in ionic conductivity dependence on composition in a variety of ionic glasses. It has suggested that the branched hydrocarbons can exhibit a higher diffusivity in zeolites with windows consisting of 12-membered rings. It has also been able to account for the contrasting variation in the ionic conductivity of ions with pressure of different diameters. Thus, the Levitation Effect unifies diverse diffusivity or conductivity dependences seen across different condensed matter phases as a function of pressure, composition, etc. Recently, quasielastic neutron scattering measurements have provided the first direct experimental evidence in support of the existence of the Levitation Effect. Apart from these he is also interested in the philosophy of science.
Awards and Honours: Professor Yashonath received the Young Associateship of the Indian Academy of Science in 1988, Associateship of International Centre for Science and High Technology in 1991, Fellowship of Indian Academy of Sciences in 1995. Member of Programme Advisory Committee of DST since 2007.