“Nano-Excitonic Transistor” Processes Data at Lightspeed 2023
What gives Marvel’s Ant-Man such powerful energy? His suit transistors boost weak signals for processing. Traditional transistors that magnify electrical impulses lose heat and impede signal transfer, reducing performance. What if a lightweight, compact, high-performance suit could conserve heat energy?
A “nano-excitonic transistor” was developed by POSTECH researchers led by Professor Kyoung-Duck Park and Yeonjeong Koo from the Department of Physics and a Russian team led by Professor Vasily Kravtsov from ITMO University. Intralayer and interlayer excitons in heterostructure-based semiconductors overcome transistor limits in this novel device.
A stack of two semiconductor monolayers with horizontal and vertical excitons.
Due to the free conversion between light and material in their electrically neutral states, excitons are key to developing a next-generation light-emitting element with less heat generation and a quantum information technology light source. In a semiconductor hetero-bilayer—a stack of two semiconductor monolayers—intralayer excitons are horizontal and interlayer excitons are vertical.
Two excitons emit optical signals with distinct lights, durations, and coherence times. Selective control of the two optical signals could permit a two-bit exciton transistor. Due to semiconductor heterostructures’ non-homogeneity, interlayer excitons’ low luminous efficiency, and light’s diffraction limit, controlling intra- and interlayer excitons in nanoscale regions was difficult.
The scientists previously proposed pushing semiconductor materials with a nano-tip to control excitons in nano-level regions. For the first time, the researchers used polarized light on the tip to remotely regulate exciton density and brightness efficiency without touching them.
An optical computer will require the nano-excitonic transistor.
This approach, which uses a photonic nanocavity and a spatial light modulator, controls excitons reversibly, minimizing semiconductor material damage. The nano-excitonic transistor can process vast amounts of data at light speed with no heat energy loss.
AI has entered our lives faster than imagined and needs massive amounts of data to learn and offer useful responses. As AI spreads, more data needs to be collected and processed. This research should suggest a new data processing approach for data explosion. “The nano-excitonic transistor is expected to play an integral role in realizing an optical computer, which will help process the huge amounts of data driven by AI technology,” said co-first author Yeonjeong Koo.