Researchers from the QuTech Institute at the University of Delft in the Netherlands have made a significant breakthrough in quantum computing. They managed to teleport information in a quantum way, paving the way for a future quantum internet.
Quantum calculation, infinite potential
First of all, it must be understood that quantum computation is completely different from classical computation, as it uses the properties of the quantum world, that is, the infinitely small. In fact, elementary particles do not behave at all in the same way as what we experience in our daily lives, therefore the researchers’ interest in their properties is in data processing. For example, they may exist in different states simultaneously.
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It is enough to compare qubits and bits to realize the potential of this technology. Bits are processed by classical computers to store information and can only exist as 0 or 1. The qubit, an analog of bits in quantum computation, can exist as 1 and 0 simultaneously, allowing a quantum computer to perform calculations, for example much more complex than its traditional counterparts.
So far, the quantum computation field is still in its infancy; but every step forward is important because it brings us closer to a world of infinite possibilities. Eventually, however, it is impossible to know when, quantum computers should be able to perform tasks in minutes that would take existing supercomputers thousands of years.
A quantum network with three nodes
The Dutch researchers involved in the study discussed today and published in the journal Nature, developed the first quantum network with three nodes in 2021, and it was the same network used for the experiment. You should know that quantum information can be transported by fiber optics, but the photons are lost over long distances, and therefore the information they contain disappears as well. Quantum teleportation of information therefore seems to be an ideal solution, but it is still necessary to succeed in implementing it.
QuTech’s three-node network is not fully connected. Located in a separate laboratory, several meters apart, each of the three nodes called Alice, Bob and Charlie contains a wealth of information made by nitrogen leisure centers, which are defective in the network’s carbon atoms in the diamond. Only one of the nodes, Bob, contains a memory qubit designed from an adjacent carbon atom. Bob is related to Alice and Charlie, but the latter two are not related, as explained in the video below:
Quantum entanglement, essential for teleportation of information
The first step in teleporting quantum information from a transmitter (Alice) to a receiver (Charlie) is to establish entanglement between their respective qubits. Quantum entanglement is a phenomenon in which two particles form a connected system and exhibit quantum states that are interdependent regardless of the distance between them.
Thus, the two cease to be individual particles with certain states of their own and become a system with a single wave function. To accomplish this, Alice establishes an entanglement with Bob, and any action that occurs in her is instantly repeated in him. Then it’s Bob’s turn to create a complication with Charlie. Result: Bob allows Alice and Charlie to establish an entanglement between them if they are not connected.
” After preparing an entanglement between Alice and Charlie, the state to be teleported is created and then executed. Then something happens that is only possible in the quantum world: After the measurement, the information on Charlie’s page disappears and immediately appears on Alice’s page. “, explains Ronald Hanson, physicist at QuTech and lead author of the study.
In other words, the information was teleported from one node to another, without crossing either spaces or fibers; in this way, it can not be lost along the way, as is the case with optical fiber, and it is very safe, an essential element for building a functional network.
A small step with big consequences
This is not the first time that scientists have achieved quantum teleportation. Five years ago, scientists from the Chinese University of Science and Technology succeeded in teleporting photons from Earth to the Micius satellite, in orbit at an altitude of 1,400 kilometers. On the other hand, the quantum teleportation of information by Dutch scientists is the first, and it is much more complex. It can actually give us a glimpse of what a quantum internet network would look like.
” In addition to the quality of the experiment, the demonstration of a sophisticated quantum communication configuration with three nodes and very complicated communication algorithms lays the foundation for its extension to scalable configurations of entanglement distribution and quantum communication, which is very promising “, Says García Ripoll, researcher at the Institute of Fundamental Physics at the Spanish National Research Council (CSIC) and co-founder of Inspiration-Q, to the daily El País.
Now researchers want to increase the number of memory qubits, which will make it possible to run more complex protocols, but also that the technology can be used outside a laboratory. Of course, this progress is only a first (small) step towards the spread of a huge quantum network, which should not see the light of day for at least ten years, but it is also not to be taken lightly.
If the quantum Internet is still a long way off, experts are already preparing for the potential dangers it represents. For example, the National Institute of Standards and Technology (NIST), located in the United States, is already working on quantum force encryption to prevent future quantum cyber attacks.