Quantum networks provide amazing data transfer speeds, but they are very fragile and complex. Scientists have used optical devices for quantum teleportation for the first time and have discovered a new way to improve Internet communication. During the experiment, the data was successfully teleported over tens of meters without loss of quality. They also learned to store in "quantum memory". Quantum mechanics describes the physical properties of nature on an atomic and subatomic scale. In particular, it explains the nature of photons - the smallest elementary particles, which are usually called quanta of electromagnetic fields, including light and radio waves.
Quantum technologies, as a rule, use special particles to move information - qubits, consisting of single atoms, electrons or protons. Quantum teleportation is the precise transmission of an indeterminate quantum state of a particle to a remote system, and is also a key element for transmitting information over long distances via the quantum Internet. Quantum networks have three remarkable properties: the impossibility of cloning, entanglement and superposition (which ordinary Internet networks cannot boast of). The quantum state of photons cannot be accurately determined (measured) without the risk of destroying it, which precludes any attempt to do so. As a result, the quantum state remains unknown, which means that there is no way to copy it. Therefore, a well-designed quantum network is inherently cloning-proof.
The main purpose of a quantum network is to allow qubits on one device to communicate with qubits on another device. And in this case, entanglement serves to encrypt the transmitted data. Entangled pairs of photons on different devices correlate with each other, so multiple readings of the quantum states of qubits allows you to create secret codes. Also, the correlation of entangled photons applies no matter how far apart they are. A group from the Delft University of Technology (Netherlands) has learned how to teleport the quantum state of a single photon to an optomechanical device consisting of billions of atoms. We are talking about an optical device that controls the mechanical movement of particles in the quantum mode. According to scientists, this achievement can be applied in signal amplifiers - special nodes that store data before they are teleported to the next nodes. Such devices also perform the function of "quantum memory". The researchers shared their test results in the journal Nature Photonics.
The researchers created a photonic qubit encoded in an arbitrary state, and then carried it through tens of meters of optical fiber to teleport this state into a quantum memory from two silicon cavities about 10 microns in size. The information was stored in the subspace of these structures until scientists restored it. The authors of the article emphasized that the teleportation technology can be used to work with optical signals of any length with minimal losses, including telecommunications fiber. It is this wavelength that leads to the lowest transmission loss, providing the maximum distance between repeater nodes.