KUROSAWA Tatsumi Chuo University, Faculty of Science and Engineering, Department of Physics, Prof, 理工学部, 教授 (80055061)
MINAMI Hidetoshi The University of Tokyo, Colloge of Arts and Sciences Department of Pure and App, 教養学部, 助手 (00190702)
|Budget Amount *help
¥144,000,000 (Direct Cost : ¥144,000,000)
Fiscal Year 1991 : ¥9,000,000 (Direct Cost : ¥9,000,000)
Fiscal Year 1990 : ¥67,000,000 (Direct Cost : ¥67,000,000)
Fiscal Year 1989 : ¥68,000,000 (Direct Cost : ¥68,000,000)
1) Crystal Growth and Refinement of Ultrapure Silver Halides, Mixed Crysitals and of Superconductive-Conjugate Photoconductive Substances ; We have prepared ultrapure AgCl_xBr_<1-x> crystals, a series of superconductive-conjugate photoconductive substances Y-Ba-Cu-O, La-Cu-O, Ba-Pb-Bi-O, Bi-Sr-Ca-Cu-O, Nd-Ce-Cu-O, Bi-SrCa (Lay) -Cu-O systems, and refined their basic substances Cu_2O, Bi_2O_3.
2) New Condensed States of Elementary Excitations in High-Speed and Highly-Resolved Optical Experiment ; We have confirmed the two-to one-phonon mode type transformation in AgCl_xBr_<1-x> via FIR reflection spectra, and particularly reexamined the temperature dependence of FIR reflection and optical absorbance of pure Cu_2O in a basic aspect of the superconductive-conjugate phenomena.
3) Nonlinear Responses, Anomalous Distribution, and Dynamics of Carriesr or Polarons at Crossed Intense Electric and Magnetic Fields ; We have newly observed an anomalous reduction in the electron-LO phonon coupling co
nstant in AgCl_xBr_<1-x> and a role of the acoustic phonons in polaron dynamics at the momentum space accumulation in piezoelectric semiconductors Cds.
4) Superconductive-Conjugate Photocondutivity due to Ploarons and Excitons and their Mechanism ; We have intensively and extensively examined the conjugative phenomena between photoconductivity and superconductivity of the Y_<3-x>-Ba_x-Cu_3-O_z, Ba_1-Pb_<1-x>-Bi_x-O_3, Nd_2-Cu_1-O_4 and Bi_2-(Sr_2Y_1)_x-Cu_2-O_z systems and their basic substance Cu_2O, Bi_2O_3 to experimentally clarify the correlation between anomalies in photoconductivity and occurrence of superconductivity. We have observed also similar correlation in C_<60> and SrCuO_2.
5) Photomagnetism due to Elementary Excitation and their Condensed States with Relaxation in Polar Semiconductors and Ionic Crystals ; We have pursued the photomagnetism by studying cyclotron resonance of polarons in Cu_2O at high density excitations and discovered a peculiar type of orbital diamagnetism which reveals an existence of mid-gap states via a new optical-cyclotron duouble resonance method.
6) Basic Concepts of Superconductive Optoelectronic Devices ; We have proposed the possibilities to constitute several of supercon ductive optoelectronic devices and apparatus by combining superconductive oxides and superconductive-conjugate photoconductors close to each other in compositions or their basic substances Cu_2O, Bi_2O_3. United State Patents on these item have been granted.
7) Theoretical Studies of Nonlinear Responses and Dyanmics of Polaron, Elementary Excitations and their Condensation, and of the Mechanism of the Superconductive-Conjugate Photoconductivity ; We have given a computer analysis of the band warping effect on the streaming and bunching phenomena in semiconductors. We have also proposed a hypothesis on the mechanism of superconductive-conjugate photoconductivity.
United States Patent (Granted), US Patent No. 4, 990, 487 ; Date : Feb. 5th, 1991 valid until Feb. 5, 2008 ; "SUPERCONDUCTIVE OPTOPELECTRONIC DEVICES", Inventor : Taizo Masumi, Assigne : The University of Tokyo.
USPTO Notice of Allowance, dated Jan. 24th, 1992, US Appl. No07/696, 999 : THE UNIVERSITY OF TOKYO, Inventor : Taizo Masumi, For : "PHOTOCONDUCTIVE-SUBSTANCE OF THE Y-BA-CU-O SYSTEM AND A METHOD FOR PRODUCING THE SAME"(AS AMENDED). Less