By Emily Ayshford

Quantum communication—where information is sent through particles, typically entangled photons—has the potential to become the ultimate secure communication channel. Not only is it nearly impossible to eavesdrop on quantum communication, those who try will also leave evidence of their indiscretions.

However, sending quantum information via photons over traditional channels, such as fiber-optic lines, is difficult: the photons carrying the information are often corrupted or lost, making the signals weak or incoherent. Oftentimes a message must be sent several times to ensure that it went through.

In a new paper, scientists with the Pritzker School of Molecular Engineering (PME) at the University of Chicago have demonstrated a new quantum communication technique that bypasses these channels altogether. By linking two communication nodes with a channel, they show that this new technique can send information quantum-mechanically between the nodes—without ever occupying the linking channel.

The research, led by Prof. Andrew Cleland and published June 17 in the journal Physical Review Letters, takes advantage of the spooky quantum phenomenon of entanglement between the two nodes and shows a potential new direction for the future of quantum communication.

The research joins a second recently published paper, where Cleland’s group entangled two phonons—the quantum particles of sound—for the first time, opening the door to potential new technologies.

“Both papers represent a new way of approaching quantum technology,” said Cleland, the John A. MacLean Sr. Professor of Molecular Engineering at Pritzker Molecular Engineering and a senior scientist at Argonne National Laboratory. “We’re excited about what these results might mean for the future of quantum communication and solid-state quantum systems.”

Read more at the Pritzker School of Molecular Engineering.

Image: Former postdoctoral fellow Audrey Bienfait was part of a team that entangled two phonons—the quantum particles of sound—for the first time, opening the door to potential new technologies. (Photo by Nancy Wong)