A Wired item from 2017 made a bold statement – we might expect the quantum internet to be among us by 2030. Perhaps it was the excitement surrounding the launch of a Chinese quantum satellite, which s ‘was produced a year before the article was published. But why could we understand this statement as “bold”? Is it impossible that the quantum internet, often seen as the future of our communications, will be massively adopted in 11 years?
Well, as the article makes clear, we don’t know much about quantum communications, let alone a quantum internet. Experts are still figuring out some of the basic aspects that surround it, from how best to convey quantum data to how to store it. So predicting this outcome for a relatively short time is rather daring.
What is the quantum internet?
Sounds like a simple question, doesn’t it? However, the answer could be more complex than you think. Like Ronald Hanson, an experimental physicist working on the subject with a team from Delft University of Technology in the Netherlands, the dish: “People talk about quantum networks to mean very different things.”
This should give you an idea of ââhow chaotic the development around the Quantum Internet is at the moment – there is no agreement even on the terms and concepts used to build it! But there are some things that can be said to understand a bit of what we mean by the quantum internet. First, it is important to discern what a quantum lattice is.
Like any network, a quantum network involves the interconnection of several nodes (devices or computers) that exchange quantum information instead of classical data. So, the second thing needed to understand the quantum internet is to know what quantum information really is.
The current model of transmitting information between our computers uses a binary system made up of 0s and 1. The string of these digits is what constitutes the information that is exchanged. Quantum information, on the other hand, relies on quantum mechanics to transmit data. By using quantum bits (or qubits) as units of information, this model is able to superimpose a 0 and a 1 in the same unit.
Although it seems rather strange and impossible, current experiments use qubits to encode classical information in something called quantum key distribution (QKD). This is the most basic use of qubits for data transmission. The next step would involve the transfer of quantum states directly between nodes via a property of quantum systems called entanglement.
When two particles of a quantum system interact, they can become entangled. Once this happens, both particles can be described with a single quantum state. In other words, any measurement applied to one particle instantly changes the state of the other particle, even when they are several kilometers apart. So instead of exchanging measurements and how to read them (as is the case with QKD), a quantum network could exchange quantum states between its nodes.
Of course, a quantum network is not the quantum Internet. For this to happen, it would take something else so that two users connected to a large network could store and exchange qubits. We’re a long way from having it, though: there are still no networks connecting quantum processors (which will turn those networks into a quantum internet), or quantum repeaters outside of a lab (which will expand the range limited transmission qubit).
Why would anyone care if we get there?
Quantum internet could change a lot of things. In its early days, it may provide a more secure environment for data transmission, as it might be impossible to decipher the state of a series of qubits without any entanglement. In addition, quantum computers could be used for scientific research, from measuring gravitational waves to the sharpness of images taken by distant optical telescopes.
Generally speaking, a quantum internet could be the respond to tasks which call for coordination, synchronization and confidentiality at their highest levels. So, this kind of internet could be the solution to one of the biggest problems we face in the digital age: the security of our data. That’s not all. The possibilities of a quantum internet could change a lot of things, including the way we communicate and even the way we vote.
How far are we from a quantum internet?
According to the Delft team of researchers, there are six steps before arriving at a quantum Internet:
1. Network of trusted nodes: This could also be considered step # 0, as nothing really âquantum-likeâ happens during transmission. In this step, users only use quantum generated codes whose encryption key is to be shared (even by the service provider).
2. Prepare and measure: Users can send and measure quantum states, but there is no entanglement. Users can share a private encryption key that no one else knows.
3. Tangle distribution networks: Users can entangle states but not store them.
4. Quantum memory networks: Quantum information can be transmitted and stored by entanglement.
5. and 6. Quantum computer networks: The nodes connected through the network are quantum computers.
So you can see where we are, just at step two (prepare and measure) in this roadmap. Chinese satellite launched in 2017 is the best effort to date for this type of transmission, since it was able to link two separate laboratories of more than 1,200 kilometers.
In other words, we are still a long way from having a fully-fledged quantum Internet. In fact, researchers’ opinions on this issue are varied, ranging from some who believe that quantum computing will not be as beneficial as everyone claims the people who believe we’ll get there – only that it will take some time. “
However, given the number of challenges ahead and the varying opinions of professionals in the field, we will likely see this Wired article get lost in the digital sands of our current internet before it reaches the Holy Land of the quantum internet.