Gate engineering Fabry-Pérot resonance in altermagnetic junctions

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• Spintronics aims to control spin-polarized currents electrically.
• Altermagnets offer a novel platform for spintronics due to their unique magnetic and symmetry properties.
• They provide spin splitting without net magnetization, magnetic fields, or spin-orbit coupling.

Purpose of the Study:

• Investigate coherent spin transport in two-dimensional d-wave altermagnetic junctions.
• Explore the potential for electrically tunable spin filtering.
• Distinguish between different d-wave altermagnetic symmetries.

Main Methods:

• Quantum scattering formalism applied to a d-wave altermagnetic junction connected to normal metal leads.
• Analysis of anisotropic exchange fields and spin-dependent effective masses.
• Modeling of Fabry-Pérot resonances for spin-up and spin-down electrons.

Main Results:

• Spin-polarized transport achieved when junction length matches spin-dependent wavelengths.
• Spin polarization is controllable via gate potential, interfacial barrier strength, and altermagnetic field orientation.
• The [Formula: see text]-wave altermagnet exhibits robust gate-controlled spin-polarized current in the tunneling regime, unlike the [Formula: see text]-wave counterpart.

Conclusions:

• Demonstrated a field-free, gate-controlled mechanism for spintronic functionality.
• Established tunable spin filtering based on crystalline anisotropy in altermagnets.
• Provided a diagnostic tool to differentiate d-wave altermagnetic symmetries.