New “Nano-Excitonic Transistor” Offers High-Performance Data Processing and Optical Computing Potential
Have you ever wondered how Ant-Man, a Marvel movie character, can produce such strong energy out of his small body? The answer lies in the “transistors” on his suit that amplify weak signals for processing. However, traditional transistors that amplify electrical signals lose heat energy and limit the speed of signal transfer, leading to degraded performance. What if it were possible to create a high-performance suit that is light and small but without the loss of heat energy? This is where researchers from POSTECH and ITMO University come in.
The team from the Department of Physics at POSTECH, and Professor Vasily Kravtsov from ITMO University has developed a “nano-excitonic transistor” using intralayer and interlayer excitons in heterostructure-based semiconductors. This solution addresses the limitations of existing transistors and offers an exciting new direction for the field of data processing.
Excitons are responsible for the light emission of semiconductor materials and are key to developing a next-generation light-emitting element with less heat generation and a light source for quantum information technology due to the free conversion between light and material in their electrically neutral states. In a semiconductor heterobilayer, a stack of two different semiconductor monolayers, there are two types of excitons: the intralayer excitons with a horizontal direction and the interlayer excitons with a vertical direction.
The team’s previous research proposed technology for controlling excitons in nano-level spaces by pressing semiconductor materials with a nano-scale tip. However, it was challenging to control intra- and interlayer excitons in nano-scale spaces due to the non-homogeneity of semiconductor heterostructures and low luminous efficiency of interlayer excitons, in addition to the diffraction limit of light.
To overcome this challenge, the team used polarized light on the tip to remotely control the density and luminance efficiency of excitons. This was achieved by combining a photonic nanocavity and a spatial light modulator, which can reversibly control excitons while minimizing physical damage to the semiconductor material. The most significant advantage of this method is that it utilizes “light” to control excitons, enabling the processing of massive amounts of data at the speed of light while minimizing heat energy loss.
As artificial intelligence (AI) continues to make inroads into our lives, it requires huge volumes of data for learning to provide useful answers for users. With the ever-increasing volume of information, there is a need for a new data processing strategy. This research proposes such a strategy, and the nano-excitonic transistor is expected to play an integral role in realizing an optical computer that can process huge amounts of data driven by AI technology.
The research, recently published in the international journal ACS Nano, was supported by the Samsung Science and Technology Foundation and the National Research Foundation of Korea. The nano-excitonic transistor is a significant step forward in the field of data processing and opens up exciting new possibilities for the development of next-generation light-emitting elements, quantum information technology, and optical computers.