Electronic Devices Div.

Materials/Physics & Electronic Devices Division

Superconducting electronic devices, using the flux quantization or Josephson effects, enable us to realize sensors with extremely high sensitivity and integrated circuits with a high speed and low power consumption. We are conducting research and development (R&D) on fabrication of thin films and junctions, design of electronic devices, device fabrication process, packaging technology and systems using Y-based high-temperature superconductors (HTS). We have successfully developed highly sensitive HTS SQUID magnetic sensors by using the state-of-art fabrication process of oxide thin film multilayers. We have also been developing systems with the HTS SQUID sensors such as those for exploration or monitoring of earth resources, non-destructive evaluation, and observation of the earth’s magnetic field.

R&D of reliable fabrication process for HTS electronic devices
Development of HTS integrated SQUIDs with high performance
R&D of packaging,cooling and noise screening technologies for HTS SQUIDs
Development of application systems such as those for exploration or monitoring of earth resources, non-destructive evaluation, and observation of the earth’s magnetic field
R&D of high-quality thin films and junctions with new superconducting materials

Development of smooth thin film multilayer structure including five oxide layers and ramp-edge Josephson junctions for HTS integrated circuits and SQUIDs

Cross-sectional SEM image for a smooth oxide multilayer (left) and schematic cross-section of multilayer HTS SQUID (right) (SSO:SrSnO3, L1ErBCO: La_0.1Er_0.95Ba_1.95Cu₃O_y).

Development of HTS integrated SQUIDs with high performance(x5-10 higher sensitivity,four orders of magnitude higher tolerance against magnetic firld than conventional HTS SQUIDs)

HTS magnetometer with integrated multi-turn input coil (left) and array of 5 ch gradiometers (right)

Development of HTS SQUID module for use of external pickup coil applicable to various systems (supported by Japan Science and Technology Agency (JST).

HTS SQUID sensor for use of external pickup coil (left) and packaged SQUID module (right).

Development of non-destructive evaluation (NDE) system using an HTS SQUID gradiometer array for multi-filamentary coated conductors (CCs) (supported by NEDO)

Principle of NDE of CC (left) and developed reel-to-reel NDE system (right).

Development of next-generation transient electro-magnetic (TEM) system using HTS SQUID for exploration of metal resources ( SQUITEM 3) (supported by JOGMEC)

Principle of TEM system using HTS SQUID (left) and developed SQUITEM 3 (right).

Development of SQUID magnetometer system for observation of change in the earth’s magnetic field due to earthquake (in collaboration with Tokyo Metropolitan Univ., Tohoku Univ. and Tierra Tecnica Inc.)

SQUID magnetometer system installed in Iwaki (left) and example of observed signals (right).

Development of iron-based thin films with oxide nanoparticles exhibiting high in-field Jc. (supported by JSPS)

Cross-sectional TEM image (left) and macroscopic pinning force Fp (right) for BaFe₂(As,P)₂ films with dispersed BaZrO₃ nanoparticles

Development of Josephson junctions and SQUIDs with iron-based superconductors (in collaboration with Prof. Hosono’s group at Tokyo Institute of Technology)

*I-V* curve for a bicrystal junction (left) and *V-φ* curve for a DC SQUID (right) made of Ba(Fe,Co)₂As₂ thin films.

Exploration or monitoring systems for earth resources (mineral, oil, geothermal reservoir)
Non-destructive evaluation (NDE) systems for industrial products and industrial infrastructure
Bio-medical testing systems such as magnetic immunoassays, magneto-cardiogram, and ultra-low-field NMR/MRI systems
Compact susceptometer
Observation system for the earth’s magnetic field

A. Tsukamoto et al., “Development of a HTS SQUID module for use with an external pickup coil”, Supercond. Sci. Technol., vol. 26, p. 015013 (2013).
T. Hato et al., “Development of HTS-SQUID magnetometer system with high slew rate for exploration of mineral resources”, Supercond. Sci. Technol., vol. 26, p. 115003 (2013).
M. Miura et al., “Strongly enhanced flux pinning in one-step deposition of BaFe₂(As_0.66P_0.33)₂ superconductor films with uniformly dispersed BaZrO₃ nanoparticles”, Nat. Commun., vol. 4, p. 2499 (2013).
S. Adachi et al., "Recent Developments of High-Tc Electronic Devices with Multilayer Structures and Ramp-Edge Josephson Junctions", IEICE Trans. Electron., vol. E95-C, pp. 337-346 (2012).
T. Katase et al., “Josephson junction in cobalt-doped BaFe₂As₂ epitaxial thin films on (La,Sr)(Al,Ta)O₃ bicrystal substrates”, Appl. Phys. Lett., vol. 96, p. 142507 (2010).
T. Hato et al., "Non-Destructive Testing of YBCO Coated-Conductor by Multi-Channel HTS SQUID Gradiometers," IEEE Trans. Appl. Supercond., vol. 19, pp. 804-807 (2009).
K. Tanabe et al., "Advances in High-Tc Single Flux Quantum Device Technologies", IEICE Trans. Electron., vol. E91-C, pp. 280-292 (2008).