First Quantum Internet Connection Established
For the first time, researchers have successfully generated, stored, and recalled quantum information, marking a significant milestone in quantum networking.
Sharing quantum information is essential for advancing quantum networks used in distributed computing and secure communication. Quantum computing holds promise for tackling significant challenges like financial risk optimization, data decryption, molecular design, and material property research.
However, the transmission of quantum information over long distances faces the obstacle of information loss. A solution is to segment the network into smaller parts connected by a shared quantum state. This approach requires a quantum memory device capable of storing and retrieving quantum information, which needs to interface with a device for generating quantum information.
Researchers from Imperial College London, the University of Southampton, and the Universities of Stuttgart and Wurzburg have developed a system connecting key quantum components, using standard optical fibers for data transmission. Their findings were published in Science Advances.
Dr. Sarah Thomas from Imperial College London commented, “Connecting these two essential devices is a significant step toward enabling quantum networking, and we’re thrilled to be the first to demonstrate this.”
Lukas Wagner from the University of Stuttgart added, “Enabling connections over long distances, even to quantum computers, is a crucial objective for future quantum networks.”
Remote communication
In conventional telecommunications, such as the internet or phone networks, information can degrade over long distances. To address this issue, these systems employ ‘repeaters’ at intervals that read and amplify the signal to maintain its integrity throughout the journey.
However, classical repeaters are unsuitable for quantum information because attempting to read and replicate the data would result in its destruction. While this provides a security advantage since quantum connections cannot be intercepted without alerting the users due to the data loss, it poses a challenge for long-range quantum networking.
To tackle the challenge of long-distance quantum networking, researchers are using entangled photons to share quantum information. Entangled photons are interlinked, so understanding one reveals information about the other. Two devices are essential: one to generate entangled photons and another to store and retrieve them.
While devices for creating and storing entangled photons exist, achieving on-demand photon generation and compatible quantum memory has been difficult. Photons have specific wavelengths, but devices often operate at different wavelengths, causing compatibility issues.
The research team developed a system where both devices operate at the same wavelength. A ‘quantum dot’ produces photons, which a quantum memory system, using a rubidium atom cloud, stores and releases with laser control.
Significantly, the devices’ wavelength matches today’s telecommunications networks, allowing transmission through standard fiber-optic cables used for internet connections.
European Partnership
Researchers from the University of Stuttgart, with support from the University of Wurzburg, developed a quantum dot light source. It was integrated with a quantum memory device from the Imperial and Southampton team at Imperial College London.
This achievement is the first successful interfacing of devices at telecommunications wavelengths, although there are more efficient standalone quantum dots and memories available.
The team plans to improve the system by ensuring uniform photon wavelengths, extending storage duration, and reducing the system’s size.
To Conclude, Dr. Patrick Ledingham from the University of Southampton highlights the importance of this breakthrough, noting the community’s previous unsuccessful attempts over five years, and credits the success to collaborative expertise and device synchronization.
Read the original article on: Phys Org
