Spin-splitting in a reflective beam off an antiferromagnetic surface.

Area of Science:

• Optics and Photonics
• Condensed Matter Physics
• Spintronics

Background:

• Linearly polarized light can be decomposed into two counter-rotating circularly polarized components.
• Antiferromagnetic surfaces exhibit unique optical properties due to spin interactions.
• Spin-splitting in reflected beams is a phenomenon influenced by material properties and incident light polarization.

Purpose of the Study:

• To investigate the spin-splitting of circularly polarized components in light reflected from an antiferromagnetic surface.
• To analytically derive expressions for the spatial shifts of spin components for p- and s-polarized incident beams.
• To determine the roles of gyromagnetism and surface impedance mismatch in spin-splitting.

Main Methods:

• Analytical derivation of spatial shift expressions for spin components.
• Consideration of p- and s-polarized incident beams.
• Numerical calculation of spin-splitting distance using a FeF2 crystal model.

Main Results:

• Spin-splitting arises from gyromagnetism and surface impedance mismatch.
• Analytical expressions for in-plane and out-of-plane shifts were obtained.
• Spin-splitting distance is significantly larger for p-incidence than s-incidence.
• In-plane splitting is much larger than out-of-plane splitting.
• Gyromagnetism is key for in-plane splitting; impedance mismatch is crucial for out-of-plane splitting.

Conclusions:

• Gyromagnetism and surface impedance mismatch are critical factors controlling spin-splitting in antiferromagnetic reflections.
• The derived analytical expressions provide a basis for manipulating infrared radiation.
• Results have implications for developing advanced infrared optical detection technologies.