Associate Professor Hideyuki Maki of the Faculty of Science and Technology of Keio University has realized the world's smallest class ultra-fine superconducting nanowires using carbon nanotubes as a template, and by making them into devices on silicon chips, the peculiarities that appear in minute superconductors. Announced that it succeeded in observing a superconducting phenomenon.This research result is a collaborative research with Satoshi Moriyama, Senior Researcher, National Institute for Materials Science, and Yoshifumi Morita, Associate Professor, Faculty of Science and Technology, Gunma University.

 Superconductivity manifests quantum phenomena in a relatively macro size and has been put to practical use in electronic devices, optoelectronic devices, quantum computers, etc., but when this superconductor is miniaturized to the nanometer order, it becomes macroscopic. It is expected that no new superconducting phenomenon will appear.However, many superconducting materials are more difficult to microfabricate than semiconductor materials, which are becoming finer, which is a factor that hinders the realization of devices using minute superconductors.

 This time, by hybridizing carbon nanotubes and superconductor niobium nitride (NbN), we succeeded in producing ultrafine superconducting nanowires with a minimum width of about 10 nanometers.Furthermore, when electrode structures were created at both ends of this superconducting nanowire and made into an electronic device, the superconducting state was broken and the resistance increased as the temperature was lowered (superconductivity-insulator transition) and magnetic flux became superconducting. We have succeeded in observing peculiar superconducting phenomena such as the phenomenon of tunneling across nanowires (quantum phase slip).

 In this research, we succeeded in producing nanowires with niobium nitride superconductors that have been put into practical use in superconducting devices, and we have also succeeded in making electronic devices on silicon chips. New applications of superconducting quantum devices such as high-sensitivity photodetectors are expected.

Keio University
Gunma University

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Gunma University was established as a new national university in 24, and has four faculties representing the northern Kanto region (4 majors in the Faculty of Joint Education, Department of Social Informatics in the Faculty of Social Informatics, 13 majors in the Department of Health Sciences, Faculty of Medicine, and 4 in the Faculty of Science and Technology). It is a comprehensive university of the department).A wide range of international […] who can tackle new difficult issues enthusiastically and creatively.

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