Experiment uncovers light's presence in multiple dimensions, as many as dozens
In a groundbreaking experiment, scientists from the University of Science and Technology of China have demonstrated that light can exist in a 37-dimensional mathematical space. The research, published in the prestigious journal Science Advances with the DOI: 10.1126/sciadv.abd8080, was led by Zhenghao Liu from the Technical University of Denmark.
The experiment involved measuring a pulse of light using a fiber-based photonic processor and precise measurement tools. The team designed relationships between three contexts solvable with 37 states, each representing a different spatial dimension. This 37-dimensional quantum system is distinct from classical spatial dimensions and spacetime dimensions in relativity.
The particles of light effectively existed in 37 dimensions at once, testing an extreme version of the Greenberger-Horne-Zeilinger (GHZ) paradox. The GHZ paradox, a concept in quantum physics that demonstrates non-classical behavior, was used to test the experiment's focus on non-locality and high-dimensional states. The GHZ paradox test demonstrated non-locality in 37 dimensions, contradicting local realism.
The significance of this discovery lies in demonstrating that a single photon can occupy 37 distinct quantum states simultaneously, represented mathematically by a 37-dimensional Hilbert space. This expands the known complexity of quantum states that light can embody, challenging and refining current quantum mechanics frameworks.
This multi-dimensional quantum encoding goes beyond the usual binary qubits (two-dimensional quantum states) typically used in quantum computing. By controlling light in so many dimensions, researchers can encode much more information into a single photon — vastly increasing information capacity and potentially enhancing quantum computing, communication, and cryptography technologies.
For future technologies, the impact includes:
- Quantum Computing: Higher-dimensional quantum states (qudits) allow more complex, dense, and potentially error-resistant computation than traditional qubits. This can improve quantum annealers and simulators to model complex systems more efficiently, as seen in cutting-edge quantum phase transition studies.
- Quantum Communication: Multi-dimensional photon states can increase security and bandwidth, since information is encoded across many degrees of freedom, making eavesdropping harder to detect and decode. This supports the development of unconditionally secure communication protocols based on entanglement and measurement disturbance principles foundational to quantum mechanics.
- Quantum Cryptography: Higher-dimensional encoding facilitates generating true quantum random numbers and robust cryptographic keys, improving encryption strength against future computational threats.
Overall, this experiment pushes the boundaries of quantum state control and opens pathways for scalable high-dimensional quantum technologies, promising advancements in computing power, secure communications, materials science, and artificial intelligence. The findings could have implications for future quantum technologies like computing and communication, suggesting that quantum mechanics may be more nonclassical than previously thought. Recent publications in early 2025 have highlighted the growing field of quantum research toward high-dimensional quantum states.
This groundbreaking research in environmental-science and data-and-cloud-computing fields could revolutionize how we perceive and utilize technology, particularly in the realm of quantum computing, quantum communication, and quantum cryptography. The discovery of a single photon occupying 37 distinct quantum states simultaneously not only expands our understanding of quantum mechanics but also challenges and refines current quantum mechanics frameworks.
