First-Time Internet-Based Quantum Teleportation Accomplished

A previously unthinkable engineering achievement has been accomplished: a quantum state of light has been successfully teleported through almost 30 kilometers (about 18 miles) of fiber optic cable while internet traffic is raging.

You might not be able to download your favorite cat videos more quickly or beat the morning traffic by beaming to work thanks to the amazing demonstration by US researchers.

However, teleporting quantum states across current infrastructure is a huge step toward improved encryption, a quantum-connected computing network, or potent new sensing techniques.

The study's lead computational engineer, Prem Kumar of Northwestern University, said, "This is really exciting because no one thought it was possible."

"Our work shows a path towards next-generation quantum and classical networks sharing a unified fiber optic infrastructure. Basically, it opens the door to pushing quantum communications to the next level."

Teleportation takes the quantum possibilities of an object in one place and, by carefully destroying it, forces the same balance of possibilities onto a similar object in another place. This technique bears a passing resemblance to the Star Trek transport systems that instantly transport passengers across time and space.

The process of entangling the two things' quantum identities still necessitates conveying a single wave of information across locations in space, even though actions that measure them cement their destinies in the same instant.

Any object's quantum state is a hazy smear of possibility that may melt into reality moments after formation, much like fairy floss in a spring rain. Without some kind of protection, the quantum significance is rapidly reduced to decoherence by electromagnetic radiation waves and the thermal bumping and grinding of moving particles.

It is one thing to protect quantum states within computers. It is much more difficult to send a single photon across optical fibers while preserving its quantum state while humming with text messages, bank transactions, and kitten videos. Hopefully, it will taste just as nice after you've thrown your quantum fairy floss into the Mississippi.

The researchers used a range of approaches that limited the photon's channel and decreased the likelihood that it would scatter and mix with other waves in order to protect the delicate state of their lonely photon from a 400 gigabit-per-second internet traffic flow.

"We carefully studied how light is scattered and placed our photons at a judicial point where that scattering mechanism is minimized," Kumar explains.

"We found we could perform quantum communication without interference from the classical channels that are simultaneously present."

Kumar's team is the first to teleport a quantum state with an actual internet stream, although other research teams have successfully transferred quantum information alongside traditional data streams in internet simulations.

Every test also points to the imminence of the quantum internet, which will provide computing engineers with a completely new set of tools to measure, monitor, encrypt, and calculate our reality in a way never possible before without having to create a new internet.

"Quantum teleportation has the ability to provide quantum connectivity securely between geographically distant nodes," Kumar states.

"But many people have long assumed that nobody would build specialized infrastructure to send particles of light. If we choose the wavelengths properly, we won't have to build new infrastructure. Classical communications and quantum communications can coexist."