Researchers at Durham University have recently made a groundbreaking discovery that could potentially revolutionize quantum computing, sensing, and our fundamental understanding of physics. In a paper published in Nature, the team announced their success in demonstrating long-lasting quantum entanglement between molecules, marking a significant milestone for the field of quantum technology.
Quantum entanglement, one of the most fascinating and mysterious phenomena in quantum mechanics, involves two or more particles becoming inextricably linked, such that the state of one particle influences the state of another, even when they are separated by vast distances. This instantaneous correlation between particles defies classical intuitions about space and time, and is fundamental to a variety of advanced quantum technologies.
Achieving Molecular Entanglement: A New Milestone
In the world of quantum mechanics, entanglement is often demonstrated with individual particles, such as photons or atoms. However, achieving this phenomenon in larger, more complex systems like molecules has long been considered a much more challenging goal. Molecules offer an array of additional physical properties, including vibration and rotation, which can potentially be leveraged for more complex quantum applications. These properties provide rich opportunities for future innovations but also present additional technical hurdles due to the inherent complexity of molecular interactions.
The team at Durham University has now demonstrated entanglement between molecules, opening the door to a range of exciting new possibilities. The researchers employed a cutting-edge technique called “magic-wavelength optical tweezers”—precisely controlled optical traps that allow for incredibly stable and finely-tuned manipulation of individual molecules. By carefully adjusting the frequency of laser light, the researchers were able to create a controlled environment where molecular entanglement could occur and be maintained for longer durations, overcoming some of the limitations of previous experiments with atoms.
Long-Lasting Stability: Key to Quantum Technologies
A significant challenge in quantum science, especially for complex systems like molecules, is that quantum states tend to be fragile. This fragility makes it difficult to maintain entanglement over long periods of time without the system collapsing due to various environmental factors, such as temperature fluctuations or interactions with external noise. In their study, the Durham University team made a key breakthrough by preventing the loss of entanglement for a time approaching one second—an extraordinary achievement considering the delicate nature of quantum states.
Professor Simon Cornish, the lead author of the study, highlighted the precision involved in the experiment, emphasizing that the entanglement was achieved using remarkably weak interactions between the molecules. Yet, even with these subtle interactions, the team succeeded in preserving the entangled state far longer than previously thought possible. This controlled stability is essential for advancing the field of quantum computing, as well as other quantum technologies that depend on long-lived quantum states.
“Our results demonstrate the incredible control we have over individual molecules. Quantum entanglement is extremely fragile, but we were able to entangle two molecules using incredibly weak interactions and prevent the loss of that entanglement for almost one second,” said Professor Cornish. “This represents a major step forward in understanding and manipulating the quantum properties of more complex systems.”
The Power of Precision Control
One of the key innovations enabling this breakthrough was the use of “magic-wavelength” optical tweezers. These optical traps are finely tuned to specific wavelengths of light, allowing researchers to manipulate and isolate individual molecules with unprecedented precision. By using the light’s electromagnetic fields, the tweezers provide a method of controlling molecules without physically touching them, maintaining their delicate quantum states in an extremely stable environment.
This precise control could lay the foundation for future advances in molecular-scale quantum operations, such as the construction of quantum computers or highly accurate quantum sensors. In particular, molecular quantum entanglement can be exploited to enhance the development of quantum memories—devices that store quantum information for long periods. Quantum memories are essential for building scalable quantum networks, which could enable new forms of communication and computing in the future.
Dr. Daniel Ruttley, a co-author of the study, explained, “This work demonstrates the enormous potential of molecules as building blocks for next-generation quantum technologies. The long-lived entanglement we’ve observed could be harnessed to create quantum computers, build more precise quantum sensors, and enhance our ability to study the quantum nature of complex materials.”
High Fidelity: A Cornerstone for Future Applications
One of the key metrics for assessing the success of any quantum entanglement experiment is “entanglement fidelity,” which measures the quality of the entanglement. The Durham University team achieved a fidelity of over 92%, an impressive result that sets a new standard for molecular entanglement experiments. Furthermore, when correctable errors were accounted for, the fidelity was even higher, providing a more reliable framework for scaling up quantum technologies based on molecular entanglement.
Achieving this level of high-fidelity entanglement is crucial for applications that require precision over extended timescales. For example, quantum sensing technologies—ranging from ultra-sensitive measurements of magnetic fields to extremely precise clocks—could benefit greatly from the kind of long-lived entanglement demonstrated in this study. The ability to perform long-duration measurements without losing coherence is a significant challenge, and this breakthrough brings us a step closer to overcoming it.
Implications for Quantum Networks
The potential applications for long-lived molecular entanglement extend far beyond computing and sensing. The Durham University team’s work could play a pivotal role in the development of quantum networks, which would allow for the storage, transmission, and processing of quantum information over vast distances. These networks could revolutionize everything from secure communication systems to distributed quantum computing, where multiple quantum computers work together as one powerful system.
In particular, quantum networks depend on quantum memories and long-lived entanglement to store and exchange quantum information between different nodes in the network. This research is crucial for addressing the challenges associated with creating scalable, reliable quantum communication networks—a key goal of quantum information science in the coming decades.
Beyond the Breakthrough: Future Directions
While the breakthrough achieved at Durham University represents a substantial leap in the field of quantum science, it is just the beginning. Researchers now have the potential to expand on this work in several critical ways. One important direction will be the exploration of different types of molecules for entanglement, potentially unlocking a wide range of quantum applications based on molecules’ varied properties. As quantum computing and sensing technologies advance, the diversity and complexity of molecules could open up new approaches to quantum processing, data storage, and error correction.
The team also plans to continue their research into improving the stability of entangled molecules, pushing the time frames for maintaining entanglement well beyond the current limit of nearly one second. Scaling up to entangle more molecules and using them in real-world applications remains a major challenge, but the controlled environment and techniques developed by the Durham team suggest that even larger systems could be possible in the near future.
Additionally, the team’s techniques may one day lead to breakthroughs in simulating the behavior of complex quantum materials. By entangling molecules in controlled environments, scientists could gain deeper insights into the behavior of molecular systems, potentially leading to the discovery of new quantum materials with unique properties that could drive future advancements in everything from electronics to energy storage.
Conclusion: A Leap Toward Next-Generation Quantum Technologies
The discovery of long-lived molecular entanglement marks a groundbreaking moment in the advancement of quantum technology. By achieving such a high degree of control over molecular entanglement and demonstrating its viability for future quantum applications, the team at Durham University has paved the way for future innovations in quantum computing, sensing, and communication. As we move toward a new era of quantum science, the applications of this work could radically change the technological landscape, enabling developments that were once thought to be far beyond our reach.
Through their continued research and exploration, scientists at Durham University and other institutions are laying the groundwork for the next generation of quantum technology, shaping the future of how we understand and interact with the very fabric of the universe.
Reference: Simon Cornish et al, Long-lived entanglement of molecules in magic-wavelength optical tweezers, Nature (2025). DOI: 10.1038/s41586-024-08365-1. www.nature.com/articles/s41586-024-08365-1