Quantum cryptography: on the path to secure communication

“Quantum technology opens the door to many new tools for information processing and communication,” says LMU physicist Professor Harald Weinfurter, who researches in the field of experimental quantum physics. “Quantum computers can perform certain tasks in a different way to and process them much faster than conventional computers. And in the domain of communication, they permit the secure exchange of information.”

A team led by the LMU professor recently tested a method for the exchange of quantum mechanical keys. “We use individual rubidium atoms,” explains Tim van Leent, doctoral candidate in Weinfurter’s Experimental Quantum Physics research group. In the experiment, the atoms are kept in different locations and are quantum mechanically entangled with each other. The locations are connected via a 700-meter-long fiber optic cable, which runs underneath the fountain on Geschwister Scholl Square.

“We were also able to show that the exchange works over a much longer distance,” says Harald Weinfurter. “This is the basis for future quantum networks that will connect quantum computers with each other.”

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