Laser-induced hole coherence in 2D antiferromagnet MPS₃ through spatial self-phase modulation

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nonlinear Optics

Background:

• Two-dimensional magnetic materials, specifically transition metal phosphorus sulfides (MPS3) with van der Waals structures, are promising for nonlinear optical applications.
• Controlling carrier coherence in MPS3 is key to understanding and enhancing nonlinear optical effects.

Purpose of the Study:

• To systematically investigate the third-order nonlinear optical responses of MPS3 (M = Ni, Fe, Mn) flake suspensions.
• To determine the effective monolayer third-order nonlinear susceptibility (χmonolayer(3)) for NiPS3 and MnPS3.
• To explore laser-induced non-local hole coherence in MPS3.

Main Methods:

• Spatial self-phase modulation (SSPM) effect was utilized to study nonlinear optical responses.
• Third-order nonlinear optical susceptibilities were measured at multiple wavelengths.
• Electronic structures were analyzed to understand the origin of excited-state holes.

Main Results:

• The effective monolayer third-order nonlinear susceptibilities (χmonolayer(3)) for NiPS3 and MnPS3 were determined for the first time.
• NiPS3 exhibited a higher χmonolayer(3) value (5.01 × 10^-17 m^2V^-2 at 405 nm) compared to FePS3 and MnPS3.
• Laser-induced non-local hole coherence was successfully generated in MPS3, with relationships between hole mobility, effective mass, and χmonolayer(3) confirmed.

Conclusions:

• This study provides new insights into the nonlinear optical properties of MPS3 materials.
• The observation of laser-induced hole coherence enriches the understanding of coherent regulation in 2D magnetic materials.
• The findings enable potential applications of MPS3 in all-optical devices.