In a first, scientists sent quantum messages a record distance over a traditional network

Scientists have sent quantum information across a record-breaking 158 miles using ordinary computers and fiber-optic cables.

- Aylin Woodward

It is the first time coherent quantum communication—an ultrasecure means of transmitting data—has been achieved using largely off-the-shelf equipment. This is a key step in expanding the accessibility of quantum communication and its use in encrypting information for more secure transmission of data, according to multiple physicists and engineers who weren't involved in the study.

"This is about as real-world as one could imagine," said David Awschalom, a professor of physics and molecular engineering at the University of Chicago who wasn't a part of the new work. "It's an impressive, quite beautiful demonstration."

Classical digital information is communicated over the internet in units known as bits that have fixed values of 1 or 0. In contrast, quantum information is transmitted in qubits, which can store multiple values at once, making quantum communications more secure.

Pittaluga and his colleagues at Toshiba Europe sent quantum information from regular computers hooked into the telecommunications network at data centers in the German cities of Kehl and Frankfurt, relaying them through a detector at a third data center roughly midway between them in Kirchfeld. The three-location setup enabled the group to extend the distance the messages were sent more than 150 miles, an uninterrupted distance only ever achieved in a laboratory environment.