Quantum information processing relies on the entanglement of multiple photons to handle vast amounts of data. However, creating these entangled photons efficiently remains a major challenge. Traditional methods either use quantum nonlinear optical processes, which struggle with scaling to large numbers of photons, or linear beam-splitting and quantum interference, which require complex and delicate setups prone to loss and crosstalk.
A research team from Peking University, Southern University of Science and Technology, and the University of Science and Technology of China recently achieved a breakthrough in this area. As reported in Advanced Photonics Nexus, they developed a new technique using metasurfaces—ultrathin, engineered structures that precisely control light’s phase, frequency, and polarization. This approach enables the creation of multiphoton entanglement on a single metasurface, making the process simpler and more efficient.
Their method works by directing multiple single photons toward a specially designed gradient metasurface from different angles. The metasurface manipulates these photons so that they interfere in a quantum manner, producing entangled photon states. This technique not only allows for the generation of various entangled states but also enables the fusion of multiple entangled photon pairs into larger, more complex groups. As a result, more quantum information can be encoded in a smaller space, potentially advancing quantum computing and communication technologies.
To read more, click here.