In a world’s first, researchers in France and the U.S. have performed a pioneering experiment demonstrating “hybrid” quantum networking. The approach, which unites two distinct methods of encoding information in particles of light called photons, could eventually allow for more capable and robust communications and computing.
Similar to how classical electronics can represent information as digital or analog signals, quantum networking systems can encode information as either discrete variables (DVs) in particles or continuous variables (CVs) in waves. Researchers have historically used one approach or the other—but not both—in any given system.
Using a complicated assembly of optical components, the team successfully produced photons in two highly entangled states. One of them arose from splitting a single photon between two different paths. The other—a so-called hybrid-entangled state—emerged from entangling a DV optical qubit with a CV qubit, which was held in a superposition of two different phases of light.