The research, which was done by a research team at the SNU College of Engineering, is hoped to be applied to the implementation of photonic quantum computers.

An illustration of the concept of time disorder prism. Provided by SNU

To separate colors present in a light ray for electromagnetic wave control, it is necessary to change the medium through which the light is propagating; placing a prism in the path of the light ray is one example.

A domestic research team has developed a technology that can freely control electromagnetic waves without the need to change the medium. The technology, which replaced the dependence on medium, a spatial concept, with the concept of ‘temporal change’, is hoped to be applied to the implementation of photonic quantum computers.

SNU College of Engineering announced on the 21^st that the research team led by Professor Nam-Kyu Park and Seon-Kyu Yu of the Department of Electrical and Computer Engineering implemented an electromagnetic prism that can freely control electromagnetic waves within a uniform medium by shifting the functional structure of electromagnetic devices to the temporal dimension, and have published the paper to ‘Nature Physics’ on the 20^th.

To control electromagnetic waves, including visible light, a structure with patterns in the scale of millimeters to manometers is required. However, the scientific community has recently deviated from this idea and presented a new technology that replaces spatial concepts with the concept of change of time. Before the study, the idea remained at the theoretical level, and there was no device with actual electromagnetic wave control.

The research team said, “Since time only progresses in one direction, and thereby only provides 1D information, it could be thought that time provides insufficient information to control electromagnetic waves freely… however, we focused on how the concept of time disorder provides many engineering possibilities”.

The research team merged the concept of time disorder with maxwells’ equations, a set of complex equations that explains electrical and magnetic phenomena, and established a theoretical frame for electromagnetic wave control. The team said, “The study is the first proof that signals and calculation functionalities that depended solely on spatial structures can be replaced with changes in time.”

Professor Yu said, “The temporal axis has many applications that have not yet been explored, unlike the spatial domain.”, and that he would “carry out the development of photonic devices that connects the spatial and temporal dimensions”.

(From left) Professor Nam-Kyu Park, SNU Department of Electrical and Computer Engineering, Professor Seon-Kyu Yu, Researcher Jung-Min Kim, Researcher Da-Young Lee. Provided by SNU

Nature Physics, DOI : https://doi.org/10.1038/s41567-023-01962-3

Source: https://ece.snu.ac.kr/community/news?bm=v&bbsidx=53348

Translated by: Do-Hyung Kim, English Editor of the Department of Electrical and Computer Engineering, kimdohyung@snu.ac.kr