Electric and spin current vortices in altermagnets

Fuente: arXiv
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Main Authors: Herasymchuk, Arsen, Hallberg, Karl Bergson, Hodt, Erik Wegner, Linder, Jacob, Gorbar, E. V., Sukhachov, Pavlo
Format: Preprint
Published: 2025
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author Herasymchuk, Arsen
Hallberg, Karl Bergson
Hodt, Erik Wegner
Linder, Jacob
Gorbar, E. V.
Sukhachov, Pavlo
author_facet Herasymchuk, Arsen
Hallberg, Karl Bergson
Hodt, Erik Wegner
Linder, Jacob
Gorbar, E. V.
Sukhachov, Pavlo
contents Altermagnets constitute a class of collinear magnets with momentum-dependent spin splitting and vanishing net magnetization. Direct observation of the characteristic altermagnetic spin splitting, however, remains challenging. Indirect signatures can be obtained via transport studies, which so far have only considered homogeneous driving fields. We propose to leverage nonuniform electric fields and spin density gradients to probe the shape and the spin polarization of altermagnetic Fermi surfaces via transport measurements. By using both a semiclassical Boltzmann approach and a lattice Keldysh formalism, we show that altermagnets excite swirling electric and spin currents whose profiles depend on the relative orientation of altermagnetic lobes with respect to the sample boundaries. These currents can be measured via magnetometry techniques. Unlike previous proposals considering the hydrodynamic regime of transport, swirling currents are observed even in the Ohmic regime and rely exclusively on the altermagnetic spin splitting, with no swirls observed in ferromagnets. The electric and spin current vortices predicted here provide a different altermagnetic signature in an experimentally accessible setup.
format Preprint
id arxiv_https___arxiv_org_abs_2507_08072
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Electric and spin current vortices in altermagnets
Herasymchuk, Arsen
Hallberg, Karl Bergson
Hodt, Erik Wegner
Linder, Jacob
Gorbar, E. V.
Sukhachov, Pavlo
Mesoscale and Nanoscale Physics
Altermagnets constitute a class of collinear magnets with momentum-dependent spin splitting and vanishing net magnetization. Direct observation of the characteristic altermagnetic spin splitting, however, remains challenging. Indirect signatures can be obtained via transport studies, which so far have only considered homogeneous driving fields. We propose to leverage nonuniform electric fields and spin density gradients to probe the shape and the spin polarization of altermagnetic Fermi surfaces via transport measurements. By using both a semiclassical Boltzmann approach and a lattice Keldysh formalism, we show that altermagnets excite swirling electric and spin currents whose profiles depend on the relative orientation of altermagnetic lobes with respect to the sample boundaries. These currents can be measured via magnetometry techniques. Unlike previous proposals considering the hydrodynamic regime of transport, swirling currents are observed even in the Ohmic regime and rely exclusively on the altermagnetic spin splitting, with no swirls observed in ferromagnets. The electric and spin current vortices predicted here provide a different altermagnetic signature in an experimentally accessible setup.
title Electric and spin current vortices in altermagnets
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2507.08072