Polar coupling enabled nonlinear optical filtering at MoS₂/ferroelectric heterointerfaces

Area of Science:

• Materials Science
• Condensed Matter Physics
• Quantum Phenomena

Background:

• Complex oxide heterointerfaces and van der Waals heterostructures are key platforms for quantum phenomena.
• The synergy between these material classes remains largely unexplored.
• Emergent functionalities arise from the unique interplay of material properties.

Purpose of the Study:

• To investigate the synergistic effects between complex oxide heterointerfaces and van der Waals heterostructures.
• To explore novel nonlinear optical phenomena at material interfaces.
• To develop new strategies for nanoscale reconfigurable optical applications.

Main Methods:

• Fabrication of heterostructures combining monolayer MoS2 and ferroelectric oxide thin films.
• Nonlinear optical measurements, specifically second harmonic generation (SHG).
• Density functional theory (DFT) calculations to understand interfacial effects.

Main Results:

• An unconventional nonlinear optical filtering effect was observed at the MoS2-ferroelectric oxide interface.
• The second harmonic generation response is modulated by ferroelectric domain wall chirality and polar domains.
• Interfacial polar alignment, not charge, spin, or lattice coupling, mediates the observed effect.

Conclusions:

• Polar symmetry plays a crucial role in tailoring optical responses at hybrid interfaces.
• This work establishes a new material strategy for designing nanoscale reconfigurable optical devices.
• The findings open avenues for exploring novel quantum phenomena in hybrid heterostructures.