Manipulating Photogalvanic Effects in Two-Dimensional Multiferroic Breathing Kagome Materials

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nonlinear Optics

Background:

• Multiferroic materials exhibit multiple tunable orders, offering unique control over symmetry-dependent nonlinear optical responses.
• Photogalvanic effects, which generate electric current from light, are sensitive to material symmetry and external fields.

Purpose of the Study:

• To investigate the selective control and switching of photogalvanic effects in two-dimensional (2D) multiferroic breathing kagome materials.
• To demonstrate the distinct responses of shift current and injection current to electric and magnetic fields in monolayer Nb3I8.

Main Methods:

• Theoretical modeling and first-principles calculations were employed to study photocurrent generation.
• Analysis focused on the shift current (real-space electron-hole shift) and injection current (momentum-space quantum metric dipole).
• The influence of electric fields (lattice breathing) and magnetic fields (valley polarization) on photocurrents was examined.

Main Results:

• Shift current in monolayer Nb3I8 was found to be largely independent of magnetic order.
• Injection current, linked to valley polarization, demonstrated tunability via magnetic fields.
• Both shift and injection currents could be reversed using an out-of-plane electric field, inducing lattice breathing.

Conclusions:

• 2D multiferroic breathing kagome structures offer tunable control over distinct photogalvanic effects.
• These materials show promise for advanced optoelectronic devices and sensors leveraging light-matter interactions.
• Selective manipulation of photocurrents via external fields opens new avenues in functional material design.