Generating Entanglement for Quantum Communications and Clock Synchronization
Abstract: Quantum communications requires reliable transmission of quantum bits (qubits) across potentially large distances. In particular, it is often necessary to produce quantum entanglement between qubits for various applications including quantum teleportation among many others. Photonic qubits are attractive for quantum communications since they do not strongly interact with one another nor with most media, allowing for low loss transmission through optical fibers, and they are readily manipulated with phase shifters and beam splitters. In spite of these advantages, their weak interactions between one another and with media means that it is difficult to produce entangled photons unless they begin in such a state when they are created. In this presentation, I will show how we can use non-destructive measurements and exploit so-called wavefunction collapse to prevent the growth of certain undesirable quantum states such that a pair of circularly polarized photons, one right and one left, can be driven into an entangled state in the polarization degree of freedom. This is done by slowly performing a beam splitter interaction with waveguides while the photons are interacting with a particular medium which will destroy them if they appear in the same waveguide. The improved rate of quantum entanglement generation lends itself to many applications, in particular quantum clock synchronization, where entanglement is distributed between a potentially large number of atomic clocks.
Bio: Ian Nodurft received his PhD from the University of Maryland Baltimore County in December of 2020 researching probabilistic quantum optics and quantum information protocols. His current work is primarily theoretical research in quantum optics with a focus on quantum information processing and quantum communications protocols. Much of his research involves interactions between light and matter. He is currently a Postdoctoral researcher at the University of Illinois Chicago’s Department of Electrical and Computer Engineering.