Figure 1. The signal photon, manipulated by the integrated photonic circuit, creates a 4D qudit represented by the set of orange spheres. Meanwhile, the idler photon, represented by the blue sphere, acts as a remote control for the signal photon.Credit: Haoqi Zhao, Yichi Zhang, Zihe Gao, Jieun Yim, Shuang Wu, Natalia M. Litchinitser, Li Ge, and Liang Feng, edited

Researchers have developed a breakthrough method for quantum information transmission using light particles called qudits, which utilize the spatial mode and polarization properties to enable faster, more secure data transfer and increased resistance to errors.

This technology could greatly enhance the capabilities of a quantum internet, providing long-distance, secure communication, and leading to the development of powerful quantum computers and unbreakable encryption.

Scientists have made a significant breakthrough in creating a new method for transmitting quantum information using particles of light called qudits. These qudits promise a future quantum internet that is both secure and powerful.

Traditionally, quantum information is encoded on qubits, which can exist in a state of 0, 1, or both at the same time (superposition). This quality makes them ideal for complex calculations but limits the amount of data they can carry in communication. Conversely, qudits can encode information in higher dimensions, transmitting more data in a single go.

Qubits vs. Qudits

Qubits and qudits are both units of quantum information, but they differ primarily in their capacity to hold information. A qubit, the basic unit used in

Figure 2. (a) The experimentally retrieved (upper row) and theoretically predicted (lower row) density matrices of two selected quantum states. (b) Theoretically (left panel) and experimentally retrieved (right panel) probability-of-detection matrix. Credit: Haoqi Zhao, Yichi Zhang, Zihe Gao, Jieun Yim, Shuang Wu, Natalia M. Litchinitser, Li Ge, and Liang Feng