Microscopic colloids are basic building blocks of soft and biological matter. They also serve as experimental test-beds of Brownian dynamics. By illuminating light-absorbing colloids with a laser beam, one can observe the so-called 'hot-Brownian motion'. This out-of-equilibrium colloidal system can form unconventional assemblies and exhibit evolutionary dynamics that can be tuned by light. In this talk, I will show how structuring optical forces can influence the dynamic assembly of hot Brownian colloids. I will also discuss transfer of orbital angular momentum of optical vortices to Brownian colloids.
G.V. Pavan Kumar is a professor of physics at IISER-Pune. He obtained his Ph.D. from JNCASR, Bangalore. Subsequently he was a postdoctoral fellow at Institute of Photonic Sciences, Barcelona, and at Discovery Park, Purdue University, USA. In 2010, he joined the faculty of IISER-Pune. His research interests are at the interface of statistical optics and soft matter physics including light scattering, optical forces and Brownian motion. He enjoys exploring physics of everyday phenomena, and history and philosophy of science. Also, he blogs on his research and research-life: https://backscattering.blog/