Chandra Vardhan E-mail: chandra.vardhan@physik.tu-darmstadt.de Phone: +49-6151-16-20745 Institution: Technical University of Darmstadt supervisor: Thomas Halfmann, Thorsten Peters

 

Project Title: Optimized preparation and investigation of stationary light pulses (SLPs) with cold atoms (WP3)

The aim of the task is to efficiently drive SLPs in a cold atomic medium of extremely high optical depth beyond 1000, as it is was recently demonstrated by the team at TUDA. A light pulse will be « frozen » and trapped in the medium like in a cavity – but without any mirrors, and released after an (almost) arbitrary holding time. The stunning phenomenon enables strong interactions between single photons, i.e. a prerequisite for any application in optical quantum information technology. We will optimize the conditions for the formation of SLPs, by driving the system in an improved coupling scheme in cold atom and by laser-cooling of the atomic ensemble in a hollow-core photonic bandgap fibre. The co-supervisor at UB^T will support the experimental investigations by simulations of coherent-adiabatic light-matter interactions and pulse propagation in the optically dense medium. The ESR will be trained about these techniques during the secondment at UB^T .

Expected Results: Demonstration of laser-cooling inside a hollow-core fibre to minimize decoherence effects, leading to a much improved SLP efficiency. With regard to applications, it will serve as an important step towards quantum nonlinear optics with SLPs such as, e.g., a quantum filter for single photons.

 

TUDA = Technical University of Darmstadt
UB^T = Université de Bourgogne Franche-Comté (theory group)