Researchers at the Max Planck Institute of Quantum Optics (MPQ) and the Technical University of Munich (TUM) have made significant progress in the path towards a quantum network by stimulating erbium atoms in crystalline silicon to emit single photons. This breakthrough could pave the way for extended networks linking quantum systems, potentially leading to a future quantum internet. Such a network would enable secure information exchange through fiber-optic connections, providing provable privacy and security.

The foundation of quantum technologies lies in harnessing quantum physical phenomena, such as particle entanglement, to develop cutting-edge applications. Quantum networks could host highly sensitive quantum sensors and fast quantum computers, capable of solving tasks that are beyond the reach of conventional computing machines. The researchers' innovative system offers key advantages in producing network nodes, cooling them, and transmitting data over long distances.

Quantum technologies rely on qubits, the elementary carriers of quantum information, connected through light to form a quantum network, analogous to the classical internet. The team demonstrated the potential of erbium atoms embedded in silicon crystals, which emit light at a wavelength ideal for quantum data transmission over long distances, offering promising capabilities for building quantum networks.

To stimulate erbium atoms to emit individual light particles in a controlled manner, the researchers used a silicon-based optical resonator with nanometer-sized holes. By exciting the atoms using laser light through an optical fiber, they achieved the emission of individual photons with desired characteristics, creating qubits for the transport of quantum information.

The utilization of crystalline silicon offers additional benefits, as this material has long been used in semiconductor manufacturing for various electronic devices. Its well-established production techniques, compatibility, and cost-effectiveness make it an attractive option for quantum network applications.

Moreover, the erbium atoms' excellent optical properties remain effective even at temperatures just a few degrees above absolute zero. These temperatures are relatively easy to achieve through cooling in a cryostat with liquid helium, facilitating practical implementation.

One of the most significant advantages of a quantum network lies in its tap-proof nature. Unlike conventional encryption methods, quantum networks offer perfect data protection. Intercepting the transmitted quantum information would result in the loss of its quantum properties, rendering the data unusable, thus ensuring complete security for sensitive information.

The recent advancements made by the MPQ and TUM researchers provide a promising step towards realizing quantum networks with a multitude of potential applications in sectors handling confidential or classified data, where data protection is of utmost importance.

Article rewritten from MCQST PR