Session 2D — Lectures by Fellows/Associates

Renee M. Borges, IISc, Bengaluru

Understanding inter-particle interactions with hybrid traps View Presentation

At room temperature, interactions between gas molecules are dominated by their kinetic energy, as is evident by the success of the classical theory of gases since Maxwell and Boltzmann’s formalization of the microscopic theory, and the advances that followed. The quantum theory of gases was developed by legends of physics, including Einstein, who built on the work of Bose on the counting of indistinguishable particles. Since then, multiple advances have followed providing a very clear understanding of the theory of dilute gases, both in the classical and quantum domains, with idealized interactions. At every step of these developments, ingenious experiments have been the arbiter of what holds and what needs to be revised. The most important goal, towards a better understanding of physics is the determination of the interaction between the constituents of the gas, be it atoms, molecules, ions or mixtures of these. Cooling and trapping of dilute gas atoms creates small ensembles of gases, which can be controlled and measured with unprecedented precision. When a dilute gas cools, its kinetic energy drops and the interactions are dominated by the inter-particle potentials. Such cooling along with trapping enables the detailed study of the inter-particle interactions. In the early years, single species experiment dominated. More recently, mixtures of gases of the same type have been studied. Our experiments at the Raman Research Institute innovated to develop hybrid traps, so that ions-atoms-molecules and light can be simultaneously trapped and interactions between these can be studied. Hybrid traps combine the technologies to confine individual species, so that simultaneous trapping of different classes of particles is made possible, in order to study diverse interactions in detail. In this talk, I shall present the new cooling mechanisms which we have discovered in our experiments, discuss the role of symmetries in the system and some pathways forward for the study of ion transport in a gas of atoms.