In new research, a device helps correct data lost at the quantum level.
The relay system catches the erroneous photons and pushes them back into the data stream.
This process amplifies the small number of missing photons as the data moves rapidly.
One of the biggest problems of our modern age is how to best transport large amounts of data in increasingly larger spaces. Now, quantum theorists propose that “teleportation” — something previously dreamed of by Star Trek and Willy Wonka — may be the quantum secret that unlocks true lossless data transfer.
In new research, scientists from the Quantum Working Group at the US National Institute of Standards and Technology (NIST) and Griffith University in Brisbane, Australia, suggest that quantum data transmission may surprise us. Their research, an experiment that captures and recovers stray photons during data transmission, appears in Nature Communications.
We’ll set up the scenario by imagining some different data scenarios. Think of the simple telegraph device, where a single wire carries a signal that transmits one pulse or quiet space at a time. These pulses travel all the way back and forth as electrons are exchanged at the molecular level. At its simplest level, this is what electricity does.
Now imagine a computer network where files are passed back and forth between servers or different workstations. The delivery of these files looks lightning fast, but in reality, different files are passed back and forth again and again. The algorithms that manage it even have “collision detection” to ensure less data loss when debris collides in the cable.
Both cases involve the passing of data. They appear to be very different in complexity, but both represent a simple paradigm: continuous flow. In these cases, the data pours out in one direction or the other like water in a kettle. Sometimes it alternates, but the flow is still continuous, through the pipe.
Here’s another thing about the continuous or linear flow of information: there are losses. Even in computer networks, packets sometimes collide or drop, and get lost. Whereas in a large-scale local fiber network, for example, light hops around within the fiber — there are some unavoidable losses due to the nature of light itself. “Loss-induced noise, such as from scattering and diffraction, is unavoidable in information transmission over long distances,” the researchers wrote.
Even for the most advanced data transmissions, like massive fiber-optic backbones connecting entire cities or countries, bouncing particles of light are what power the entire technology. These technologies lose photons, so finding ways to reduce losses is a huge industry in itself. The more data we send, the tiny losses add up to the true amount of data loss.
To study the loss, the scientists first set up an experiment where an unimportant photon was bounced to a location where it would be deliberately lost in interfering noise. To control the losses, they first applied a device called a noise-free linear amplifier. When it works, the device appears to “catch” the erroneous photon, bring it back into a quantum state, and amplify it into a healthy portion of the data.
“An efficient long-distance quantum communication channel requires a mechanism to reduce this loss of information, which is exactly what we did in our experiments,” researcher Sergei Slussarenko said in a statement. “Our work enables a so-called quantum relay, a key ingredient in such long-distance communication networks.”
As a next step, the researchers hope to test this approach for long-distance quantum cryptography. After this, they can start dreaming of a truly secure global quantum network.