Researchers at QuTech — a collaboration between Delft University of Technology and the Netherlands Organization for Applied Scientific Research — recently took a big step toward making that a reality. For the first time, they succeeded in sending quantum information between non-adjacent qubits on a rudimentary network. Their findings were published in the journal Nature.

While modern computers use bits, zeroes, and ones, to encode information, quantum computers us quantum bits or qubits. A qubit works in much the same way as a bit, except it’s able to hold both a 0 and a 1 at the same time, allowing for faster and more powerful computation. The trouble begins when you want to transmit that information to another location. Quantum computing has a communications problem.

Today, if you want to send information to another computer on a network, that’s largely accomplished using light through fiber optic cables. The information from qubits can be transmitted the same way but only reliably over short distances. Fiber optic networks have a relatively high rate of loss and rely on cloning bits and boosting their signal in order to transmit over significant distances. Qubits, however, can’t be copied or boosted. That means that when and if information is lost, it’s lost for good, and the longer the journey the more likely that is to happen.

That’s where Hiro Nakamura comes in, or at least his quantum counterpart. In order to reliably transmit quantum data, scientists use quantum teleportation, a phenomenon that relies on entanglement or what Einstein called “spooky action at a distance.”

Using that spooky connection, scientists can transmit information between the two particles and that information appears at one particle and vanishes at the other instantly.

This has some important implications for the future of communication. First, using quantum teleportation networks avoids the threat of packet loss over fiber optic cables. Second, it effectively encrypts the information at Alice’s end. In order to decode the information, you need to know the result of the calculation Charlie performed. The third thing builds upon the first; despite the immediate transfer of quantum information, we are still bound by the speed of light. As you know, the cosmic speed limit isn’t just a suggestion, it’s the law. Sending the calculation information to Alice in order to decode the information relies on more traditional communications bound by light speed. No getting around it.

While this is an important step toward a quantum internet, in order to build the sorts of networks we’ll need for everyday use, we’re going to need a lot more nodes. But, hey, even today’s global communications network started with a single telephone.

Read more: https://www.newscientist.com/article/2281591-quantum-data-link-established-between-two-distant-chinese-cities/#ixzz70aAdbima

Scientists are edging closer to making a super-secure, super-fast quantum internet possible: they’ve now been able to ‘teleport’ high-fidelity quantum information over a total distance of 44 kilometres (27 miles).

Both data fidelity and transfer distance are crucial when it comes to building a real, working quantum internet, and making progress in either of these areas is cause for celebration for those building our next-generation communications network.

In this case the team achieved a greater than 90 percent fidelity (data accuracy) level with its quantum information, as well as sending it across extensive fibre optic networks similar to those that form the backbone of our existing internet.