Magnetic Dynamics Variation Induced by the Meissner Effect in Superconductor/Ferromagnet Heterostructures.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Investigating magnetic dynamics in superconductor/ferromagnet/superconductor heterostructures is crucial for spintronics.
• The physical origins of observed magnetic phenomena in these heterostructures remain debated.

Purpose of the Study:

• To explore the impact of superconducting (S) layers on the magnetization dynamics of a ferromagnet (F) layer.
• To elucidate the role of the Meissner effect in S/F/S heterostructures.

Main Methods:

• Fabrication of superconductor/ferromagnet/superconductor (S/F/S) and superconductor/platinum/ferromagnet/platinum/superconductor (S/Pt/F/Pt/S) heterostructures.
• Measurement of ferromagnetic resonance (FMR) field and inhomogeneous linewidth (μ₀ΔH₀) as a function of temperature.

Main Results:

• Ferromagnetic resonance field of the F layer shifted to lower fields below the superconducting critical temperature (Tc).
• Inhomogeneous linewidth (μ₀ΔH₀) broadened below Tc.
• The observed effects persisted even with platinum interlayers, suggesting a non-spin-current-mediated mechanism.

Conclusions:

• The Meissner effect in superconducting layers generates a spatially inhomogeneous magnetic field below Tc.
• This field is responsible for the observed superconductivity-induced resonance field shifts and linewidth broadening.
• Findings clarify origins of these phenomena and may advance superconducting spintronic devices.