Quantum Optics Seminar: Zofia Borowska

Quantum Teleportation of Weak Coherent Polarization States Coexisting on Deployed Metropolitan Fiber 

In this work, we demonstrate quantum teleportation across Deutsche Telekom's metropolitan fiber testbed in Berlin, using commercial components. A Bell-state measurement between 795 nm photons from a weak coherent source and a warm-atom entangled photon source transfers the input polarization onto an O-band telecom photon, which then traverses a 30 km field-deployed fiber loop with automatic environmental compensation. We achieve an average fidelity above 91%, preserved even when C-band classical traffic co-propagates in the same fiber, pointing toward practical quantum networking over existing telecom infrastructure.