Deterministic Out-of-Plane Spin Polarization Enabled by Altermagnetic Filtering of Critical Spin Fluctuations
Year: 2026
Type: preprint
Abstract: Spin current with out-of-plane polarization is essential for manipulating perpendicular magnetization but are typically suppressed by symmetry in conventional spin–orbit systems. Here we demonstrate a mechanism to generate and control such spin polarization by combining magnetic transitions with altermagnetic symmetry filtering. Near the Curie temperature of CrTe2, enhanced critical spin fluctuations produce a dense ensemble of angular-momentum-carrying excitations. Passing through the altermagnet CrSb, they are filtered into a spin current with a well-defined out-of-plane component, exerting a nonlinear torque on an adjacent Fe layer. The magnitude and sign of the polarization are continuously tunable via the current direction relative to the crystal lattice, reflecting Berry-curvature-driven spin textures. This approach establishes combining magnetic phase transitions with altermagnetic spin filter as tunable spin sources and provides a general route to engineering three-dimensional spin polarization.
Source: Research Square
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7165663123