Physics Colloquium --- Quantum Light-Matter Interaction: Towards High-speed Quantum Communication

Physics Tea at 4:00 followed by Professor Lorenz's talk at 4:15. Abstract: The interaction of light and matter at the quantum level can provide novel methods of communication that are completely secure. I will present two types of components that are necessary for quantum communication: entangled photon sources and quantum memories. An entangled photon source generates photons that exist in a delicate superposition, which is useful for sending information without fear of eavesdropping. I will present an entangled-photon source based on commercially available optical fiber and recent theoretical results showing how one can tailor the photons' properties to make them useful for applications in quantum communication and computation. Quantum memories are devices capable of controllably storing and releasing a single photon. To date, quantum memories have operated with bandwidths that limit data rates to megahertz. I will present results demonstrating the coherent storage and retrieval of low-intensity light pulses with spectral bandwidths exceeding 1 GHz and recent work towards the development of a THz quantum memory.