Abstract
Optical trapping and optical tweezers have been used to confine and control micron and nano sized objects based on light-matter interactions. When multiple particles are in a single optical trap, they interact with one another and form organized arrays referred to as optical matter. Optical matter is a novel formation of matter where the interparticle interactions are governed by an external light source and its properties can be tuned with the properties of light, such as intensity, polarization, and phase. Optical matter systems give rise to novel dynamical properties, including non-equilibrium processes, non-conservative forces, and non-reciprocal interactions.
In this talk, I will demonstrate the fundamental properties and applications of optical matter and use them to design functional materials that can do work at the nano-scale. Non conservative interactions will be shown to give rise to a non-reciprocal net-force in an optically bound hetero-dimer. More generally, when there are many identical particles forming an array, a single intruder particle is expelled from the array due to non-reciprocal interactions. This principle is used to segregate mixtures of optically trapped nanoparticles by their size and material. By tuning the properties of the optical trap, the steady-state behavior of the optical matter system can be controlled and used to create an optical matter array that operate as a stochastic machine. This machine operates by converting the incident spin angular momentum of light into scattered orbital angular momentum, which is then coupled into a probe particle that experiences a non-conservative driving force in the presence of Brownian forces.