It is our great honor to be able to organize the 20th RIES-Hokudai International Symposium and to welcome all the participants.

Research Institute for Electronic Science (RIES) started as “Research Institute of Ultrashort Waves” in 1943 is now conducting a diverse range of science including optical science, material science, life science and mathematics under the mission of development of new interdisciplinary fields. For this purpose, we carry out several programs to encourage active interactions between researchers in different research fields. The International Symposium having been held annually since 1999 is one of the most important events.

The symposium each year has been symbolized by a single "Kanji" character. The “Kanji” in 2019 is the character “稀” [ki] which generally denotes “rare”, “uncommon”, and “phenomenal”. “稀” [ki] may also have a meaning of “uniqueness”. Newly synthesized compounds with “uncommon” structures have much chances to possess novel properties. Observations of “rarely” occurring phenomena often trigger the establishment of new theories. It is always important in science to focus on “稀” materials and phenomena. We can say that all the important scientific works are unique and distinguished or “稀”, but we want to emphasize again the importance of uniqueness in scientific works in each field to be discussed for the development of new interdisciplinary fields. At the moment when a unique scientific work meets another unique work in other fields, a new interdisciplinary field opens. With this keyword “稀” in mind as a common theme, let us implement interdisciplinary discussions during this Symposium.

I expect the present symposium would be a fruitful one for all the participants to be much stimulated and to get an inspiration of new science.

Representing the organizing committee of 20th RIES-Hokudai International symposium,
Prof. Nobuyuki Tamaoki,
the chair of 20th RIES-Hokudai International Symposium