Quantum computers promise. The real revolution will come with the advent of the quantum Internet, which is already on its way.

• In July 2020, the US Department of Energy announced its strategy for developing the quantum Internet.

• The key resource that makes distributed quantum computing possible is entanglement.

Quantum technologies go beyond quantum computers. We talk about them a lot because they have undergone some impressive changes in the last five years, but there is life beyond these very complex machines. Also quantum internet is being created. In fact, this large-scale quantum communications infrastructure is already being built. In July 2020, the US Department of Energy released its strategy to promote the development of technologies needed to deploy a quantum internet.

And hand in hand with this announcement also came a firm commitment to initially invest $625 million in the project. China and the United States are the two great powers that are devoting the most resources to the development of quantum communications, but Europe is also contributing to the discipline with very significant successes. Deploying a quantum communications infrastructure with global coverage and reach comparable to the Internet we currently use will allow us to transmit large amounts of information almost instantly.

Moreover, the data transfer will be carried out in a secure manner as the interweaving between the nodes involved in the data exchange is broken if it is compromised in any way. Even if someone is just watching it. Both promises sound great, but it would be wise to temper our initial enthusiasm for one good reason: the quantum Internet is not intended to replace the Internet we use now.

The Quantum Internet is Coming

When it arrives, and we have good reason to predict that it will, it will coexist with the Internet with which we are all familiar, just as quantum computers are designed to coexist in perfect harmony with classical supercomputers. This reflection leads us to ask in what applications the quantum concept of the Internet makes sense, and the answer follows naturally from the two properties of this network that we just examined: its ability to transmit large amounts of data. in the instantaneity and inherent invulnerability of quantum communications.

Stephanie Simmons is a physicist, former postdoctoral fellow at Harvard University, and co-founder of the quantum communications company Photonic. He recently took part in an event organized by Economist Impact and left us with several statements that may help us better understand what is the potential of the quantum internet. His company aims to produce photonic-linked silicon spin qubits as a strategy that promotes a modular and scalable architecture.

“The key resource that makes distributed quantum computing possible is entanglement (…) Its distribution is critical in all quantum network use cases (…) If we manage to properly distribute entanglement, we will be able to run algorithms on a large scale. and faster,” says Simmons. Another important point that this expert offers us is that the implementation of a distributed system of qubits connected by photonic bonds allows entanglement of any two qubits. Of course, as long as there is a photonic connection between them, because entanglement must be accomplished.

This phenomenon has no equivalent in classical physics and consists in the fact that the states of the quantum systems involved, of which there may be two or more, are the same. This means that these objects are actually part of the same system, even if they are physically separate. Actually, the distance does not matter. If two particles, objects or systems are entangled as a result of this quantum phenomenon, when we measure the physical properties of one of them, we instantly condition the physical properties of the other system with which it is entangled. Even if he is on the other side of the Universe.

Everything we have seen so far in this article allows us to foresee that quantum computers connected by photonic links will presumably form a quantum internet, which will have capabilities unattainable from the network with which we are all currently familiar. In fact, if this infrastructure finally flourishes and is implemented correctly, scalability will no longer be an issue. And it will be possible to connect so many qubits together that, in a certain sense, the quantum Internet itself will behave like a giant quantum computer equipped with millions of qubits. I hope these ideas come to life. Fingers crossed.

Image | IBM

Additional information | Quantum Insider

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