Optical inter-site spin transfer probed by energy and spin-resolved transient absorption spectroscopy

Area of Science:

• Condensed matter physics
• Materials science
• Ultrafast magnetism

Background:

• Optically driven spin transport offers efficient magnetization manipulation without angular momentum dissipation.
• Understanding ultrafast spin dynamics is crucial for advanced magnetic technologies.

Purpose of the Study:

• To investigate optical inter-site spin transfer (OISTR) as a dominant mechanism in CoPt alloy magnetization dynamics.
• To link OISTR to electronic structure and transient absorption changes.

Main Methods:

• Joint theoretical and experimental investigation.
• Measurement of helicity-dependent absorption in the extreme ultraviolet (EUV) range.
• Analysis of transient spin-split density of states.

Main Results:

• OISTR from Platinum (Pt) to Cobalt (Co) is identified as a dominant ultrafast magnetization mechanism.
• Helicity-dependent absorption changes correlate directly with spin-split density of states.
• The origin of OISTR is linked to minority states above the Fermi level.

Conclusions:

• OISTR is a key phenomenon in the optical control of multi-component magnetic systems.
• This mechanism provides a pathway for efficient manipulation of magnetization dynamics.
• The findings advance the understanding of light-matter interactions in magnetic alloys.