Chinese researchers have developed a silicon photonic quantum chip capable of generating high-dimensional multipartite entangled states, marking a new step forward in the development of scalable quantum technologies.
The research team successfully created three-party, four-dimensional GHZ and W entangled states with fidelities of 93.2 per cent and 90.1 per cent respectively. The results demonstrate a new approach to producing complex high-dimensional quantum systems and expanding their potential applications, as reported by
Global Times, a TV BRICS partner.
Quantum entanglement is one of the key resources in quantum technologies, allowing quantum particles to maintain interconnected states even when separated. While traditional research has largely focused on two-dimensional quantum systems, high-dimensional entanglement can carry more information and improve the stability and accuracy of quantum information transmission.
A conventional qubit has two basic states, usually represented as 0 and 1. High-dimensional quantum information units can contain additional states. For example, a four-dimensional quantum unit includes four basic states: 0, 1, 2 and 3.
Compared with traditional two-dimensional entanglement, high-dimensional systems provide greater information capacity, stronger resistance to interference and improved efficiency in quantum information processing. They may also help simplify quantum computing architectures and increase computational performance.
During the study, researchers developed a universal definition of high-dimensional W entangled states, expanding the theoretical framework for designing larger quantum systems. The approach can be applied to different numbers and dimensions of quantum information units, providing a basis for future development of high-dimensional quantum technologies.
The team also proposed a scalable method for generating high-dimensional entangled states by using multiple distinguishable states of individual photons combined with delayed quantum measurements. This method allows a single photon to carry several quantum information units while preserving quantum entanglement.
To test the technology, scientists conducted experiments using a programmable silicon photonic quantum chip measuring 16 by 1.5 millimetres. One photon carried two quantum information units, while another carried a third unit. Together, the three units formed a three-party, four-dimensional quantum system.
The researchers successfully generated both GHZ and W entangled states, demonstrating the potential of the approach for creating larger quantum systems. The work combines theoretical development with practical chip-based implementation, providing a foundation for future advances in quantum communication, quantum computing and precision measurement.