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arXiv · 2109.13181

Half-integer Shapiro Steps in Strong Ferromagnetic Josephson Junctions

Yunyan Yao·Ranran Cai·See-Hun Yang·Wenyu Xing·Yang Ma·Michiyasu Mori·Yuan Ji·Sadamichi Maekawa·Xin-Cheng Xie·Wei Han
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Abstract

We report the experimental observation of half-integer Shapiro steps in the strong ferromagnetic Josephson junction (Nb-NiFe-Nb) by investigating the current-phase relation under radiofrequency microwave excitation. The half-integer Shapiro steps are robust in a wide temperature range from T = 4 to 7 K. The half-integer Shapiro steps could be attributed to co-existence of 0- and pi-states in the strong ferromagnetic NiFe Josephson junctions with the spatial variation of the2 NiFe thickness. This scenario is also supported by the high-resolution transmission electron microscopy characterization of the Nb/NiFe/Nb junction.

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Yunyan Yao, Ranran Cai, See-Hun Yang, Wenyu Xing, Yang Ma, Michiyasu Mori, Yuan Ji, Sadamichi Maekawa, Xin-Cheng Xie, Wei Han. 2021-09-27. Half-integer Shapiro Steps in Strong Ferromagnetic Josephson Junctions. https://doi.org/10.1103/physrevb.104.104414

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