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arXiv · 2603.23235

Enhanced spin-current generation in Dirac altermagnets through Klein tunneling

Tomas T. Osterholt·Lumen Eek·Cristiane Morais Smith·Rembert A. Duine
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Abstract

Altermagnets have recently emerged as a new platform for spintronics applications, offering spin-split electronic bands despite vanishing net magnetization. Here, we investigate spin-current generation in Dirac altermagnets and identify Klein tunneling as an efficient mechanism for enhancing spin transport. Using a low-energy Dirac model combined with scattering theory, we demonstrate that Klein tunneling in altermagnets is strongly spin-dependent and can be used to effectively control the electronic spin-current polarization by, for instance, adjusting the height, width and orientation of the potential barrier. Finally, we explore how the l-wave symmetry of the Dirac altermagnet shapes the spin-current polarization and transmission, focusing especially on the d- and g-wave cases. Particularly promising results are obtained for the g-wave Dirac altermagnet, as it is found that the presence of a potential barrier can significantly boost the spin-current polarization, even when the intrinsic polarization due to the spin-split band structure is vanishingly small. For a barrier implemented via electrostatic gating, such a mechanism would in turn allow the spin-current polarization to be switched on and off via a gate voltage.

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Tomas T. Osterholt, Lumen Eek, Cristiane Morais Smith, Rembert A. Duine. 2026-03-24. Enhanced spin-current generation in Dirac altermagnets through Klein tunneling. https://arxiv.org/abs/2603.23235

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