Superconducting Electronics Group


Group Outline and Primary Goal

The Superconducting Electronics Group performs the following research activities:

  • Search for novel superconductors and development of new superconducting materials
  • Theoretical and experimental work towards the elucidation of the mechanism of high-critical-temperature superconductivity
  • Research and development for industrial use of high-temperature superconducting wires


Key Themes of Research

  1. Development of superconducting materials that have higher Tc, or possess other interesting or useful properties
  2. Design and trial production of copper oxide high temperature superconducting cables for industrial applications
  3. Development of basic technology for industrial use of iron-based high-temperature superconducting materials
  4. Elucidation of the mechanism of superconductivity in high-temperature superconductors represented by copper oxide and iron compound superconductors
  5. Research for the development of new functional substances and new devices, and development of physical property evaluation methods

High-Pressure Synthesis
Here, material synthesis is performed under extreme conditions. This technique is useful in the search for high-throughput materials.

Zone Melting
This is a technique for growing single crystals of materials such as high-Tc cuprates with the largest dimensions and best qualities.

First-Principles Electronic Structure Calculation
The calculation of the electronic structure of abnormal superconducting materials.

High-Pressure Measurement of the Physical Properties
This allows us to alter the structure of materials without introducing disorder; provides a systematic scan of the structural parameter space for the development and optimization of novel materials.

The Quantum Monte Carlo Method
The elucidation of electronic correlation effects

Prototype of superconducting wire using Iron-based superconductor


Our Technologies and Equipment

  • Condensed-matter theory, band calculation
  • Analytical theory of superconductors and numerical simulation technology
  • High-pressure material synthesis
  • Single-crystal growth using floating-zone method
  • The measurement of transport phenomena under high pressure
  • Production technology of superconducting wire by PIT method

Articles

・S. Ishida, et al., "Unique defect structure and advantageous vortex pinning properties in superconducting CaKFe4As4", npj Quantum Materials 4, 27 (2019)
・I. Hase, T. Yanagisawa, Y. Aiura and K. Kawashima; Possibility of Flat-Band Ferromagnetism in Hole-Doped Pyrochlore Oxides Sn2Nb2O7 and Sn2Ta2O7 Phys. Rev. Lett. 120 (2018) 196401.
・S. Ishida, et al., "Effects of post-growth heat treatment on electronic phase diagrams and critical current densities of Ba(Fe1−xCox)2As2 and BaFe2(As1−xPx)2 single crystals", PHYSICAL REVIEW B 98, 054511 (2018)
・A. Iyo et al., “New-Structure-Type Fe-Based Superconductors: CaAFe4As4 (A = K, Rb, Cs) and SrAFe4As4 (A = Rb, Cs)“ J. Am. Chem. Soc. 138, 3410 (2016).