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Superconductor Quantum Phase Engineering Group

Much attention has been paid to electronic devices utilizing intrinsic properties of superconductors, for example, superconducting quantum interference devices (SQUID) and terahertz EM emission/detection devices. Many of them are based on the manipulation of quantum phases. The objective of the Quantum Phase Engineering Group is to study material developments, device fabrications, measurements and physical comprehensions of phenomena to be applied to superconducting electronics by making use of quantum phases in oxide and metal superconductors.
Scanning SQUID microscopy and STM are powerful tools for revealing vortex dynamics. Developments of advanced SQUID measurement systems are carried out. Research on vortex dynamics by using such tools is also one of our important objectives. As for terahertz devices, widely studied single crystal based ones and thin film based ones are investigated. Further, we study physical properties of phase difference solitons in multiband and multicomponent superconductors and its device applications. Development of the advanced materials applicable to such various devices is the key activity of the group. For power applications, fabrication processing of superconducting wires and joints are studied by taking an advantage of techniques accumulated for thin film growth such as control of in-plane texture and quasi-equilibrium crystal growth. In the light of materials informatics, simulations are targeted as well.

Specialized Research Field

THz Generation using intrinsic Josephson junctions

THz Generation has been studied using intrinsic Josephson junctions embedded in a piece of Bi2Sr2CaCu2O8 crystal. We have developed a high power, narrow line width, frequency tunable wide-band generator at the negative resistance region in the current-voltage characteristics based on the matching of ac-Josephson and cavity resonant frequencies.

"A “HOT SPOT” in doughnut shape, playing a key role to get variable cavity sizes. (Hubagin Wang)" Image

A “HOT SPOT” in doughnut shape, playing a key role to get variable cavity sizes. (Hubagin Wang)

Understanding of vortex dynamics and finding a new functional

Ratchet effect has been found in the interaction between pancake vortices (perpendicular field) and Josephson vortices (parallel field). We will invent new functional vortex devices with low energy consumption and high-speed, based on fundamental research of vortex dynamics.

"Josephson/Pancake vortices and the Ratchet effect. (Shuichi Ooi, Kazuto Hirata)" Image

Josephson/Pancake vortices and the Ratchet effect. (Shuichi Ooi, Kazuto Hirata)

Fabrication of STM-SQUID

Fabrication of STM-SQUID with a spatial resolution less than 1 µm under low temperature and magnetic field.

"Surface/Magnetic images observed by STM-SQUID(Minoru Tachiki)" Image

Surface/Magnetic images observed by STM-SQUID(Minoru Tachiki)

Contact Information

Superconductor Quantum Phase Engineering Group
1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047 JAPAN
E-Mail: ARISAWA.Shunichi=nims.go.jp(Please change "=" to "@")
National Institute for Materials Science (NIMS)
1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, JAPAN