ContentsOverview of Materials Science Research
Hideaki Takayanagi
Materials Science Laboratory
The Materials Science Laboratory (MSL) aims at discovering new quantum phenomena and creating new concepts by producing new materials. Toward these goals, the five research groups of MSL investigate various materials, ranging from inorganic ones such as high-Tc superconductors and photonic crystals to organic materials like silicon polymers and biopolymers.
(1) Molecular Science Research Group
Research into high-luminescent optical devices and new-functional
electron devices using new organic materials.
(2) Bio-Science Research Group
Research into information processing devices using a novel
architecture based on neural function.
(3) Superconducting Thin Films Research Group
Development of thin-film growth technology for high-Tc
superconductors using molecular beam epitaxy method.
(4) Superconducting Quantum Physics Research Group
Research into Andreev reflection and the charging effect in supercondctor-semiconductor
Structures, and the development of quantum devices using these
effects.
(5) Nano-Structure Materials Research Group
Development of optical devices with unique beam propagation
using the fabrication technology of three-dimensional photonic crystals.
Three major results obtained in fiscal year 1998 are reported in the following pages. We developed an easy method for controlling the screw-pitch of helical polysilane copolymers (Topic 1). The result will induce an important industrial application.
It is very difficult to fabricate a Josephson junction with the structure of a superconductor/insulator/superconductor (S/I/S) using high-Tc materials. However, we found that some kinds of high-Tc superconductors behave as an S/I/S-type Josephson junction array by themselves with excellent performance (Topic 2). This will lead to new kind of devices using the intrinsic Josephson effect.
The final topic is concerned with the optical crystal which is similar to conventional crystals, where electrons propagate. It is said that photonic band structure and band gap form in the photonic crystal and the crystal behaves as an insulator because of the gap. We succeeded in observing band gap in a three-dimensional photonic crystal using a direct method to measure the band structure by optical beam propagation (Topic 3).