Spin-polarized scanning tunneling microscopy: breakthroughs and highlights

Area of Science:

• Surface science
• Condensed matter physics
• Nanotechnology

Background:

• Scanning tunneling microscopy (STM) provides atomic resolution imaging.
• Adapting STM with magnetic tips enables surface magnetism studies.
• Spin-polarized STM (SP-STM) utilizes the tunneling magnetoresistance effect for contrast.

Purpose of the Study:

• To illustrate the working principle of SP-STM.
• To showcase the capabilities of SP-STM in studying magnetic surfaces.
• To present key experiments performed using SP-STM.

Main Methods:

• Utilizing magnetic probe tips in STM.
• Exploiting the tunneling magnetoresistance effect for contrast.
• Applying SP-STM to various magnetic surfaces including Cr(001), Fe double-layers, and Mn/W(110).

Main Results:

• Demonstrated atomic-resolution imaging of surface magnetism.
• Revealed magnetic domain patterns (e.g., 50 nm periodicity in Fe films).
• Identified an antiferromagnetic spin cycloid on Mn/W(110) through combined experiments and theory.
• Showcased SP-STM's suitability for studying dynamic magnetic properties like spin relaxation times.

Conclusions:

• SP-STM is a powerful technique for atomic-resolution surface magnetism studies.
• SP-STM provides insights into complex magnetic structures and dynamics.
• The technique is versatile for investigating diverse magnetic materials.