Today’s internet is not the last frontier of communication. Physicists have created a new method of communication in which information can be sent on what’s called a “quantum internet,” a network of quantum devices delivering hyper-secure communications, ultra-accurate timekeeping, and dozens of other applications scientists can’t even begin to anticipate. To even try is like expecting Alan Turing to predict TikTok.
Scientists from QuTech — a collaboration between Delft University of Technology and the Netherlands Organization for Applied Scientific Research, which built the world's first quantum network last year — published the breakthrough in a paper in the journal Nature on Wednesday. The team successfully sent quantum information between two non-neighboring nodes (think: quantum routers) using a concept long-discussed by quantum physicists and Star Trek fans alike: teleportation.
“Teleportation is like what you know from science fiction,” the paper’s co-author, Ronald Hanson, tells Inverse. Hanson is an experimental physicist, co-founder of QuTech, and a Distinguished Professor at Delft University of Technology. “The information disappears on my side and appears on your side, but it doesn’t travel the space between us…It’s an extremely powerful method for sending information.”
This ability to teleport is what fundamentally forms a quantum network — the deep physics that holds the entire thing together. Without the ability to transfer information via teleportation, the quantum internet wouldn’t be possible. However, this “teleportation” isn’t exactly akin to obliterating Captain Kirk’s atoms only to rematerialize them on some newly discovered class-M planet. This isn’t organic matter we’re talking about — it’s information, or more specifically, quantum bits (or qubits).
Today’s internet uses bits, a combination of 0s and 1s, to form everything online — including this very website. Qubits are 0s and 1s existing at the same time in a state called “superposition,” which enables quantum computers that can answer complex math problems in minutes that would take a powerful supercomputer 10,000 years to figure out.
The quantum internet is also inherently secure, because qubits rely on the physical properties of photons rather than vulnerable code, so they can’t be intercepted. In other words, it’s nearly impossible to hack quantum messages.
So where does teleportation fit in? To tap into the full potential of quantum computers, they need to be networked together, but qubits can’t be sent the same way as traditional bits. While bits travel via light (fiber optic cables) or radio waves, photons carrying qubits quickly degrade using those same methods. What’s more, because qubits can’t be amplified or copied (“cloned” as quantum physicists like to say), the signal can’t be boosted either. So scientists found a different way to send quantum information by using teleportation, all brought to you by the mysterious phenomenon known as quantum entanglement.
Quantum entanglement is when two particles are intrinsically linked so when you read one, you immediately know the state of the other — whether it’s in the next room or the next galaxy. This basic quantum principle is such a mystery that even Albert Einstein, a top-notch physicist, and all-around smart dude, tossed up his hands and just described it as “spooky action at a distance.” But because of this “spooky action,” if a network could establish entanglement across vast distances, say from the U.S. to China, qubits could teleport without losing any fidelity.
“The whole process of teleportation doesn’t have a classical analog… there’s no such thing,” Hanson says. “It’s the entanglement that makes this whole process possible.”
The way quantum teleportation works is simple and complex at the same time (as only quantum mechanics can be), and this study shows how teleportation in a quantum internet works in miniature. In the study, QuTech scientists teleported information between three nodes. Information was sent from node C, or Charlie, to another point called node A, or Alice. To do that, the researchers used an intermediary, node B or Bob.
First, Alice and Bob become entangled across an optic cable using their quantum processors, and Bob stores this entangled state on what’s called a “memory qubit.” Bob then entangles with Charlie, and by using what QuTech calls a “quantum mechanical sleight of hand,” Bob performs a special measurement on his processor and swaps its entanglement with Charlie to the Alice entanglement stored on its memory qubit. Alice and Charlie now share an entangled state, but this isn’t the end of the process — Scotty has only just warmed up the teleporter.
Charlie then prepares the quantum bit to be teleported and finally carries out a joint measurement with the message and its entangled state with Alice. This is where the true power of the quantum internet comes in. When the information disappears on Charlie’s side, it immediately appears on Alice’s side. After some quantum decrypting, the information is now available.
Although the quantum internet will achieve technological wonders that are impossible by today’s standards, it’s unlikely that one day all our laptops and iPhones will just go “quantum.”
“Most people don’t think quantum internet will replace the internet,” Hanson says. Instead, he envisions a future where our classical internet and the quantum internet work in tandem — with quantum teleporters on standby when you need to send an extra-secure communication, for example, or if you’re dealing with other highly sensitive information. But streaming your latest Netflix binge will likely still be a job for your standard, run-of-the-mill internet.
Although the QuTech study focused only on a simple three-node network, Hanson says the idea can be expanded to include as many nodes as needed. The next phase of research is to test the method outside the lab and teleport information at further distances. It’s just the beginning of the process of scaling up the tech that will power up the quantum communication era.