Friday 28 March 2025
Researchers at Shenzhen Institute for Quantum Science and Engineering have made a significant breakthrough in the development of optical quantum memories, achieving record-long coherence times and lifetimes for rare-earth ion-based systems.
The team has successfully fabricated high-quality Eu3+:Y2O3 transparent ceramics, which are essential for harnessing the unique properties of rare-earth ions. These ions can exist in long-lived spin states, making them ideal for storing and manipulating quantum information.
To achieve this feat, the researchers employed a novel fabrication process that involves co-precipitation, ball milling, vacuum sintering without sintering aids, hot isostatic pressing, and subsequent post-air annealing. This multi-step approach allowed them to produce ceramics with exceptional optical properties, including narrow inhomogeneous linewidths and long-lived spin states.
The Eu3+:Y2O3 transparent ceramics were then subjected to a range of experiments designed to test their coherence properties. The team found that the 7F0 →5D0 transition exhibited an optical T2 time of 421.5 ± 10.5 microseconds, which is significantly longer than previously reported values for similar systems.
Furthermore, the researchers demonstrated the ability to store coherent light signals in these ceramics using an atomic frequency comb (AFC) memory protocol. This protocol involves creating a periodic frequency structure within the optical transition and then manipulating it to store and retrieve quantum information.
The AFC memory protocol allowed the team to store light signals for up to 5 microseconds, which is a significant improvement over previous demonstrations of optical quantum memories. The researchers also achieved a storage efficiency of 0.11%, which while not yet optimal, is an important step towards developing practical quantum memory devices.
The significance of this breakthrough lies in its potential to enable the development of large-scale quantum communication networks and other applications that rely on the manipulation of quantum information. Rare-earth ion-based systems have long been considered promising candidates for quantum information processing due to their unique properties, but achieving high-quality fabrication and precise control over their coherence properties has proven challenging.
The Shenzhen team’s achievement represents a major milestone in this field, as it demonstrates the ability to fabricate high-quality Eu3+:Y2O3 transparent ceramics with exceptional coherence properties. This breakthrough opens up new avenues for research into optical quantum memories and has significant implications for the development of practical quantum technologies.
Cite this article: “Record-Breaking Optical Quantum Memory Achieved Using Rare-Earth Ion-Based System”, The Science Archive, 2025.
Quantum Memory, Optical Quantum Memory, Rare-Earth Ions, Eu3+:Y2O3, Transparent Ceramics, Coherence Properties, Quantum Information Processing, Atomic Frequency Comb, Quantum Communication Networks, Quantum Technologies.
