'Nano Antenna' for Quantum Optics Made with Dominoes

[Asia Economy Reporter Junho Hwang] Domestic researchers have developed a nano-optical antenna that densely concentrates light to observe quantum optical phenomena occurring at the nanometer scale.

The Ministry of Science and ICT announced on the 3rd that Professor No Joon-seok's research team at Pohang University of Science and Technology developed a nanoantenna with atomic-level resolution and the nanofabrication technology to produce it. The related research paper was published on the 2nd (local time) in Materials Today, an international journal in the field of materials engineering.

The research team, inspired by the domino game, developed a continuous domino lithography technique. This technology uses photoresist, a polymer material whose chemical properties change under light or electron beams, to create pillar-shaped structures and intentionally topple them to form desired nano patterns?a new type of nanofabrication technology.

The team succeeded in constructing sharp nanostructures using this technology and also developed a bowtie-shaped nanoantenna. Based on electron beam lithography technology commonly used for fabricating nanostructures, the team deliberately incorporated the structural toppling phenomenon observed in dominoes into the photoresist structures. They utilized the ideally sharp points where the toppled lines meet to create pointed nanostructures with curvature below 1 nanometer.

To explore new optical phenomena, it is essential to precisely fabricate and arrange structures smaller than 10 nm. However, due to the physical diffraction limits of electrons and ions, it has been challenging to fabricate and process nanostructures smaller than 10 nanometers with precision and sharpness.

Additionally, the research team experimentally realized an ultra-high sensitivity biosensor capable of detecting single molecules using the bowtie-shaped nanoantenna.

The research team stated, "Extreme light-focusing nanoantennas are expected not only to advance extreme nano-optical research but also to pioneer new fields of nanotechnology such as nanolithography technology with single-nanometer resolution and highly efficient single-photon sources for quantum information technology."