Alexander X. Gray, Florian Kronast, et al.
Applied Physics Letters
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 radio-frequency 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 the coexistence of 0 and π states in the strong ferromagnetic NiFe Josephson junctions with the spatial variation of the NiFe thickness. This scenario is also supported by the high-resolution transmission electron microscopy characterization of the Nb/NiFe/Nb junction.
Alexander X. Gray, Florian Kronast, et al.
Applied Physics Letters
Ruisheng Liu, See-Hun Yang, et al.
Applied Physics Letters
Stefano Bonetti, M.-J. Sher, et al.
IRMMW-THz 2016
Shehrin Sayed, Cheng Hsiang Hsu, et al.
Physical Review Applied