Curated by RSF Research Staff
Quantum memories for a quantum internet network
Research on quantum communication is very active and a major improvement has been made recently in terms of Earth-to-Satellite Quantum Teleportation and Quantum Communications via Satellites. Another important subject concerns quantum memory, an essential element to build any quantum system and in particular for quantum networks.
Quantum networks built from optical fiber-linked quantum nodes open manifold opportunities like high-speed quantum cryptography networks, large scale quantum computers and quantum simulators. The requirements for a scalable quantum node technology are (i) storing quantum information in a quantum memory, and (ii) on demand conversion of this information into single photons traveling along the network interconnects. Many different physical platforms for quantum memories are currently under investigation, ranging from phonons in solids to atomic Bose-Einstein-condensates.
" The combination of a simple setup, high bandwidth and low noise level is very promising for future application in quantum networks."
Janik Wolters - University of Basel, Swiss
Physicist Janik Wolters and his team based at University of Basel have developed a quantum memory in warm Rb vapor with on-demand storage and retrieval .
The researchers were able to store information and read them out again later without altering their quantum mechanical properties too much. This memory is working with single photons emitted by semiconductor quantum dots. Vapor cell memories offer an excellent compromise between storage efficiency, storage time, noise level, and experimental complexity, and atomic collisions have negligible influence on the optical coherences. Operation of the memory is demonstrated using attenuated laser pulses on the single photon level. Straightforward technological improvements can boost the end-to-end-efficiency and increasing the optical depth and exploiting the Zeeman substructure of the atoms will allow such a memory to approach near unity efficiency.
In the future, quantum networks could lead to unconditionally secure communication in metropolitan areas and network computing able to solve complex problems such as the simulation of large physical, chemical and biological systems.https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.060502