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arXiv · 2409.17718

Optical control of spin-splitting in an altermagnet

Sangeeta Rajpurohit·Revsen Karaalp·Yuan Ping·Liang Z. Tan·Tadashi Ogitsu·Peter E. Blöchl
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Abstract

Manipulating and controlling the band structure and the spin-splitting in the newly discovered class of magnetic materials known as 'altermagnets' is highly desirable for their application in spintronics. Based on real-time simulations for an interacting multiband tight-binding model, we propose optical excitations as an effective way to selectively control the spin-splitting of an altermagnet. The consistent treatment of electronic interactions and electron-phonon coupling in the model allows for a systematic study of the effect of these interactions on the spin-splitting of the altermagnet in the ground as well as in the excited-state. Our simulations reveal that optical excitations modify the band structure and thus lead to significant changes in the spin-splitting within 50 fs. The relative spin-splitting in the conduction band grows up to four times in the optically excited altermagnet. We disentangle the roles of Coulomb $U$ and $J$ in the enhancement of the spin-splitting in the photoexcited state. Our study elucidates the potential for exploiting optical control of spin-splitting gaps to obtain desirable properties in altermagnets on the fastest possible timescales.

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Sangeeta Rajpurohit, Revsen Karaalp, Yuan Ping, Liang Z. Tan, Tadashi Ogitsu, Peter E. Blöchl. 2024-09-26. Optical control of spin-splitting in an altermagnet. https://arxiv.org/abs/2409.17718

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