Light-Tunable Ferromagnetism in Atomically Thin Fe_{3}GeTe_{2} Driven by Femtosecond Laser Pulse

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Intrinsic ferromagnetism in two-dimensional (2D) van der Waals (vdW) crystals is a recent discovery.
• Achieving tunable intrinsic 2D vdW magnetism is a key goal for spintronics.

Purpose of the Study:

• To investigate the effect of femtosecond laser pulses on the magnetic properties of few-layered Fe3GeTe2 (FGT).
• To explore the potential for light-driven tuning of magnetism and enhancing the Curie temperature (Tc) in 2D vdW materials.

Main Methods:

• Modulation of magnetization and magnetic anisotropy energy (MAE) of few-layered FGT using femtosecond laser pulses.
• Analysis of the relationship between laser excitation intensity and magnetic ordering, including saturation magnetization and coercivity.

Main Results:

• Femtosecond laser pulses significantly modulate the magnetization and MAE of FGT.
• Increasing laser intensity linearly increases saturation magnetization and monotonically decreases coercivity.
• Observed light-driven ferromagnetism at room temperature (300 K), exceeding the material's intrinsic Curie temperature (Tc ≈ 200 K).

Conclusions:

• Optical doping effect due to laser excitation alters the electronic structure, leading to tunable ferromagnetism.
• This study presents a novel method for optically tuning 2D vdW magnetism and enhancing Tc.
• Findings promote the development of spintronic devices operating at or above room temperature.