A technology has been developed that can generate a bright quantum light source at a desired location at room temperature without the need for cumbersome cryogenic equipment such as existing liquid nitrogen, liquid helium, or temperature control equipment, and it is expected to contribute to the commercialization of light-based quantum communication in the future.

The National Research Foundation of Korea (NRF, President Jeong-Hye Noh) announced on the 22nd that a joint research team (co-authors Professor Moon-Seok Jeong of Sungkyunkwan University, Professor Hong-Gyu Park of Korea University, etc.) including Professor Kyung-Deok Park (Ulsan National Institute of Science and Technology, first author Researcher Hyeong-Woo Lee), Professor Jun-Seok Noh (Pohang University of Science and Technology, joint first author Dr. In-Ki Kim) and others have developed a technology that can stably generate a quantum light source of a two-dimensional material at room temperature.

In order to actually use it as a light source for a device, it was necessary to control the location of the quantum light source, which exists randomly at any location. Another challenge that had to be overcome was the possibility of generating and detecting quantum light sources only at low temperatures.

Existing nano-optical resonators can control the position of the light source, but have limited spatial resolution, and probe-enhanced photoluminescence nanomicroscopes have high resolution, but it is difficult to generate quantum light sources.

Accordingly, the research team combined these two and designed a light control and measurement system using a new concept called resonant nanomicroscopy.

Through prior research, a nano-optical resonator with an atomic-level sharp bow-tie shape was fabricated using a continuous domino lithography process, enabling the generation of a quantum light source from a two-dimensional semiconductor material at a desired location.

In this study, by combining a photoluminescence nano-microscope with this resonator and inducing a triple antenna effect, a quantum light source was generated with high efficiency, and the quantum light source could be detected with a spatial resolution of approximately 15 nanometers (about one-tenth of the thickness of a human hair) at room temperature.

In fact, it was confirmed that the quantum light source created in this way was 40,000 times brighter than a semiconductor quantum light source that did not apply the antenna effect.

This means that the light emitted from one LED with the triple antenna effect is equivalent to the brightness of light emitted from 40,000 existing LEDs.

The research team expects that it can be used as a light source for quantum information communication devices and as a tool for understanding quantum materials at the nanoscale.

It is also explained that it can be applied to detect weak optical signals of various nanomaterials with high sensitivity.

To further improve the stability and quality of quantum light sources, the research team is conducting comparative studies on various plasmonic structures.

The results of this research, which was supported by the New Researcher Program and Mid-career Researcher Program of the Ministry of Science and ICT and the National Research Foundation of Korea, were published in the international academic journal in the field of materials physics, Advanced Functional Materials.It was published (online) on June 18 in ‘Journal of Functional Materials’.