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[ Professor ] Yoichi Uehara

[ Associate Professor ] Satoshi Katano

Research Activities

Our main interest lies in studying the physical and chemical phenomena that take place in nanometerscale regions and their applications in nanophotoelectronic devices. Development of novel probing methods is also targeted.

Nano-photoelectronics (Prof. Uehara)

The material properties of individual nanostructures are investigated through their optical responses to the local excitation induced by electron tunneling in a scanning tunneling microscope (STM). In this method, unlike conventional electric measurements, attainable temporal resolution is not limited by the signal levels. Hence, the material properties are explored with high spatial and temporal resolution. Efficient excitation of light confined in nanostructures is possible in the spectral range from THz to PHz by electron tunneling. This confined light is efficiently converted to free (i.e., propagating) light by the presence of the tip. By utilizing such properties, one can realize efficient and broadband optical sources and detectors.

Research topics

  • Exploration of material properties of individual solid-state nano-structures in spatial, energy, and time axes.
  • Development of STM light emission spectroscopy with ps time resolution.
  • •Investigation of various electromagnetic phenomena in nanometer-scale spaces, and their engineering applications.
  • Development of efficient and broad-band light sources and detectors.

Nano-photomolecular Electronics (Assoc. Prof. Katano)

Process and operation principles of the next-generation molecule-based electronic devices are investigated to break through the limit of downsizing that the current Si technology will reach in the near future. By using electron tunneling in STM, one can control the locations of individual atomic and molecular species on a solid surface and even induce chemical reactions in them. The physical, chemical and electronic properties of the species processed in such a way are investigated by using abilities of STM itself. The optical proper-ties are also analyzed by STM light emission spectroscopy. By combining these techniques, we explore novel molecule-based electronic devices.

Research topics

  • Optical excitation of a single atom and molecule.
  • Controlling of the chemical reaction and geometry of a single molecule.
  • Molecular electronics based on the nano molecular assembly.