Direct probing of the exchange interaction at buried interfaces

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Interactions between magnetic moments at interfaces significantly influence layered magnetic structures.
• Understanding these interactions is crucial for phenomena in low-dimensional solids.
• Direct probing of buried magnetic interfaces remains a challenge.

Purpose of the Study:

• To propose and demonstrate a novel method for probing magnetic exchange interactions at buried interfaces.
• To utilize spin-polarized electrons and magnons for interface characterization.
• To determine interface exchange parameters through experimental and computational analysis.

Main Methods:

• Employing spin-polarized electrons to probe magnetic excitations (magnons).
• Leveraging the collective nature of magnons, particularly low-energy interface-localized modes.
• Combining experimental data with first-principles calculations for parameter determination.

Main Results:

• Demonstrated that weak interface coupling localizes the low-energy magnon mode at the interface.
• Showcased that this interface magnon mode, with its long lifetime and spectral weight, is detectable by electrons.
• Successfully determined interface exchange parameters by comparing experimental results with theoretical calculations.

Conclusions:

• The proposed method enables direct probing of magnetic exchange interactions at buried interfaces.
• This technique is sensitive to interface properties, especially under weak coupling conditions.
• The developed approach holds potential for advancing the spectroscopy of buried magnetic interfaces.