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Updated: Feb 10, 2026
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Direct Imaging of Laser-driven Ultrafast Molecular Rotation
Published on: February 4, 2017
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Asymmetric Spin Canting and Demagnetization Dynamics Driven by Laser Fields in Two-Dimensional Altermagnets.
Shuo Li1, Ran Wang1, Thomas Frauenheim1,2
1Institute for Advanced Study, Chengdu University, Chengdu 610106, China.
Nano Letters
|February 9, 2026
Summary
Researchers explored ultrafast magnetization dynamics in 2D altermagnets (AMs). Laser pulses induced asymmetric demagnetization in Fe2WTe4, creating a photoinduced ferrimagnetic state tunable by laser polarization.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Ultrafast Phenomena
Background:
- Ultrafast magnetization dynamics are understood in conventional magnets.
- Altermagnets (AMs) present a new frontier for exploring light-matter interactions.
- The behavior of 2D semiconducting AMs under laser excitation is largely unknown.
Purpose of the Study:
- Investigate laser-induced ultrafast magnetization dynamics in 2D altermagnets.
- Explore the potential for light-driven control of magnetism in these materials.
- Uncover the microscopic mechanisms behind laser-induced spin dynamics in Fe2WTe4.
Main Methods:
- Employed real-time time-dependent density functional theory (rt-TDDFT).
- Simulated the interaction of laser pulses with a 2D semiconducting altermagnet (Fe2WTe4).
- Analyzed sublattice-resolved demagnetization and spin dynamics.
Main Results:
- Demonstrated asymmetric demagnetization between Fe sublattices in Fe2WTe4.
- Achieved a photoinduced ferrimagnetic state with a net magnetization of ~0.3 μB per unit cell.
- Observed tunable, non-collinear spin dynamics and spin canting controlled by laser polarization.
Conclusions:
- Laser pulses can induce unique ultrafast magnetization dynamics in 2D AMs.
- Momentum-dependent spin-splitting and optical intersite spin transfer effect (OISTR) drive these dynamics.
- Light offers a pathway for controlling spin textures and achieving novel magnetic states in 2D AMs.
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