Ultrafast electrically controlled magnetism in charge-order-induced ferroelectric altermagnet

TL;DR

This paper predicts that LiV$_2$F$_6$ exhibits ultrafast electrically controlled magnetism due to its altermagnetic and ferroelectric properties, enabling rapid magnetic switching for advanced electronic applications.

Contribution

The study introduces LiV$_2$F$_6$ as a novel material hosting both altermagnetism and ferroelectricity, demonstrating ultrafast electric control of magnetism through first-principles calculations.

Findings

Electric polarization reversal induces band spin-polarization switching.

Polarization reversal occurs in 15 femtoseconds.

LiV$_2$F$_6$ can be experimentally synthesized and used for ultrafast magnetic control.

Abstract

The altermagnetism with antiparallel spin alignment exhibits anisotropic spin splitting and may possess an insulating state with a high Neel temperature, while the charge-order-induced ferroelectricity has ultrafast electric polarization switching. Considering that altermagnetism requires breaking space inversion,, the physical foundation for exploring ultrafast electrically controlled magnetism in altermagnetic ferroelectric materials is thus established. In this Letter, based on symmetry analysis and first-principles electronic structure calculations, we predict that LiV$_2$F$_6$ is a material that simultaneously hosts altermagnetism and charge-order-induced ferroelectricity. Since both the altermagnetism and ferroelectricity originate from charge order, LiV$_2$F$_6$ should exhibit strong magnetoelectric coupling. Our calculations indeed demonstrate that electric polarization reversal can induce band spin-polarization switching in LiV$_2$F$_6$. Moreover, time-dependent density functional theory calculations show that the electric polarization reversal in LiV$_2$F$_6$ occurs in 15 femtoseconds. Consequently, ultrafast electrically controlled magnetism can be realized in LiV$_2$F$_6$. Given that LiV$_2$F$_6$ has already been experimentally synthesized, our work provides a promising material platform for achieving ultrafast electrically controlled magnetism, which might have significant implications for the design of future electronic devices.