Research
Outline
When the size of a solid is reduced to a few nanometers (1/1,000,000 mm), the electrons in the solid exhibit new properties that are different from those in a normal-sized solid. For example, if the same substance is reduced to a size of several nanometers, it will emit various colors such as red, green, and blue, depending on the size. Such a phenomenon can be understood as a result of the conspicuous appearance of the "quantum nature" of electrons, which has not been seen in normal-sized substances.
In our laboratory, we are studying new physical properties and phenomena that appear by spatially controlling the electron wave function in "nanomaterials" at the nanometer scale. Furthermore, by using these research results, we aim to establish guidelines for designing nanomaterials with "new optical functions."
By studying in detail from single nanoparticles to superstructures of nanoparticle aggregates and photonic crystals, we will be able to understand the fascination of nanomaterials science, and design and design unique new functional materials that are not bound by material types. We believe that we can pioneer the field of nano-quantum elemental science.
Research topic
In our laboratory, we experimentally study the dynamic quantum optical properties of solids driven by high-intensity laser light using spatially resolved spectroscopy and ultrafast time-resolved spectroscopy. By making full use of ultrafast laser spectroscopy and single-dot spectroscopy, we aim to clarify the physical properties of nanomaterials and solar cell materials with new optical functions, and to develop photonics technologies that lead to new light sources (quantum light sources and laser pulse light sources).
Nanophotonics Spectroscopy
By combining ultrafast laser spectroscopy (time-resolved spectroscopy) and single nanoparticle microscopic spectroscopy (spatial-resolved spectroscopy), we investigate optical properties of nanomaterials and quantum properties for quantum light sources such as single-photon sources. We are also developing light sources using state-of-the-art lasers and spectroscopic technologies (THz-STM, etc.).
Nonlinear Optical Spectroscopy
Using high-intensity terahertz and mid-infrared pulsed light, we are investigating high-order harmonic generation from solid crystals. Since light with a frequency that is an integral multiple of the incident optical field is generated, nonlinear light is expected to develop new photonics technologies such as light sources with a wide range of wavelengths from infrared rays to X-rays and attosecond (10-18 seconds) pulse light sources.
Quantum Coherent Spectroscopy
We are conducting precise observations of elementary excitations (excitons, polarons, magnons, etc.) in matter. We are exploring new quantum optical functions by inducing phase transitions and forming phase-matched quantum states (coherent states) by strong excitation by laser light.
