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Updated: Aug 19, 2026

Fabrication of Magnetic Platforms for Micron-Scale Organization of Interconnected Neurons
Published on: July 14, 2021
Significant magnetoresistance enhancement due to a cotunneling process in a double tunnel junction with single
H Sukegawa1, S Nakamura, A Hirohata
1Department of Materials Science, Graduate School of Engineering, Tohoku University, Aoba-ku, Sendai 980-8579, Japan. a4td9507@stu.material.tohoku.ac.jp
Abstract:
We fabricate CoFe/AlOx/CoFe/AlOx/CoFe ferromagnetic double tunnel junctions and observe spin-dependent tunneling phenomena. A middle CoFe layer becomes discontinuous by forming CoFe particles two dimensionally, of which the average diameter is evaluated to be 2.0-4.5 nm from cross-sectional transmission electron microscopy images. Below 50 K, a Coulomb gap is observed in current-voltage curves, and both magnetoresistance ratios and resistances are found to increase significantly with decreasing temperature. This indicates that a cotunneling process is dominant within the gap, which agrees very well with theoretical prediction [Phys. Rev. Lett. 80, 1758 (1998)].
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