Spin-dependent transport in a driven non-collinear antiferromagnetic fractal network

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Non-collinear magnetic textures break spin-sublattice symmetry, inducing spin-splitting effects.
• Understanding spin-dependent transport in novel magnetic materials is crucial for spintronics.

Purpose of the Study:

• To investigate spin-dependent transport properties in non-collinear antiferromagnetic fractal structures, specifically the Sierpinski Gasket (SPG) triangle.
• To propose and analyze a method for enhancing spin polarization in these fractal networks.

Main Methods:

• Utilized Green's function formalism and the Landauer-Büttiker prescription for calculating spin-resolved transport quantities.
• Incorporated the effect of time-periodic driving fields using the Floquet-Bloch ansatz.
• Investigated dependencies on driving field parameters, scattering strength, and interface sensitivity.

Main Results:

• Initial studies on SPG triangles showed weak spin polarization despite differing spin-up and spin-down currents.
• A significant enhancement of spin polarization was achieved by applying a time-periodic driving field.
• The proposed method demonstrated a novel spin-filtering effect from an unpolarized source in a fractal network.
• Finite spin polarization was observed for various spin-quantization axes.

Conclusions:

• A time-periodic driving field offers a viable route to significantly enhance spin polarization in non-collinear antiferromagnetic fractal structures.
• This work introduces a new approach for achieving spin-filtering effects in fractal networks, opening avenues for spintronic applications.
• The findings encourage exploration of other fractal structures for unconventional spintronic properties and experimental realization.