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arXiv · 2401.15424

Interplay of altermagnetism and weak ferromagnetism in two-dimensional RuF$_4$

Marko Milivojević·Marko Orozović·Silvia Picozzi·Martin Gmitra·Srdjan Stavrić
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Abstract

Gaining growing attention in spintronics is a class of magnets displaying zero net magnetization and spin-split electronic bands called altermagnets. Here, by combining density functional theory and symmetry analysis, we show that RuF$_4$ monolayer is a two-dimensional $d$-wave altermagnet. Spin-orbit coupling leads to pronounced spin splitting of the electronic bands at the $Γ$ point by $\sim 100$ meV and turns the RuF$_4$ into a weak ferromagnet due to non trivial spin-momentum locking that cants the Ru magnetic moments. The net magnetic moment scales linearly with the spin-orbit coupling strength. Using group theory we derive an effective spin Hamiltonian capturing the spin-splitting and spin-momentum locking of the electronic bands. Disentanglement of the altermagnetic and spin-orbit coupling induced spin splitting uncovers to which extent the altermagnetic properties are affected by the spin-orbit coupling. Our results move the spotlight to the non trivial spin-momentum locking and weak ferromagnetism in the two-dimensional altermagnets relevant for novel venues in this emerging field of material science research.

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Marko Milivojević, Marko Orozović, Silvia Picozzi, Martin Gmitra, Srdjan Stavrić. 2024-01-27. Interplay of altermagnetism and weak ferromagnetism in two-dimensional RuF$_4$. https://doi.org/10.1088/2053-1583%2Fad4c73

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