Department of Informatics and Electronics

Quantum semiconductor electronics

  • (9) 産業と技術革新の基盤をつくろう


In nanometer-sized structures (quantum nanostructures), physical parameters such as electron orbitals, charge, and spin are quantized, which in turn give rise to a variety of novel physical phenomena. Our research aims to discover and elucidate novel physics that emerge in such "quantum semiconductors" and to control them to make applications in electronics.

Instructor / Laboratory

Electronic properties of quantum nanostructures in the THz region and their device applications:

 Many physical parameters in semiconductors are encompassed in the THz/fs region. To elucidate the physics in quantum nanostructures, it is extremely useful to study the interaction between electrons and electromagnetic waves in the THz region. We are using THz spectroscopy to elucidate the electronic properties and conduction mechanisms in quantum nanostructures. This allows us to clarify the limits of transistors and to study the dynamics of Bloch oscillators. Furthermore, we are working on new THz

Nanotechnology and nanoscience toward the realization of single molecule transistors:

The use of single molecules to electronic devices has been discussed for a long time . In recent years, it has finally become possible to fabricate and measure single molecule devices controlled at the atomic level. We establish fabrication technologies for metal electrodes with a gap of less than 1 nm to access single molecules and study THz dynamics of single molecule devices.

■Development of high-speed and high-sensitivity terahertz detectors using MEMS:  The development of high-sensitivity and high-speed terahertz detection technology that does not require cooling to cryogenic temperatures is essential for the widespread use of terahertz technology, which is attracting attention in various fields such as basic science, medicine, pharmaceuticals, and safety and security fields. We are developing an uncooled, sensitive, and high-speed terahertz detector based on a micro-electromechanical structure (MEMS). A slight temperature rise due to heat generation induced by terahertz incident light is sensitively read as a shift in the resonance frequency of the MEMS beam resonator structure fabricated by semiconductor microfabriation technologies.

Highly Efficient Thermal Electron Emission Cooling Devices Using Semiconductor Quantum Structures:

Modern LSIs and optoelectronics have made great progress by achieving high-density integration and high-speed operation of devices. However, heat generated inside the devices has begun to have a significant impact on device operation and reliability, greatly hindering the development of electronics. Therefore, it is no exaggeration to say that highly efficient cooling technology for devices is the key to the future development of electronics.
We are studying thermionic emission cooling structures that cool electrons efficiently by properly designing the tunneling and thermionic emission effects in semiconductor thin-film structures.