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Characterization of Anisotropic Leaky Mode Modulators for Holovideo
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Quadruple Moiré Pockets in Lateral Heterobilayers: Programmable Phononic Reconfiguration and Anomalous Second
Suman Kumar Chakraborty1, Purbasha Ray1, Frederico B Sousa2
1Quantum Materials and Device Research lab, Materials Science Centre, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721302, India.
Advanced Materials (Deerfield Beach, Fla.)
|November 26, 2025
Summary
This study introduces novel quadruple moiré-pockets in 2D transition-metal dichalcogenides, enabling precise control over twist-angle for tuning quantum phenomena and strain-mediated effects in opto-straintronics.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Optics
Background:
- Moiré-engineering in 2D transition-metal dichalcogenides (TMDs) is key to exploring correlated quantum phenomena.
- Simultaneous control over twist-angle and material combinations to tune phonons, excitons, and their interactions is limited.
Purpose of the Study:
- To present scalable, quadruple moiré-pocket platforms using vertically stacked TMD heterostructures.
- To investigate the impact of twist-angle and material combinations on lattice relaxation, phonon properties, and optical responses.
Main Methods:
- Fabrication of monolayer MoS2-WS2 and MoSe2-WSe2 lateral heterostructures via chemical vapor deposition.
- Controlled variation of twist-angle (θ) from 0° to 60°.
- Characterization using angle-resolved photoemission spectroscopy (ARPES) and second-harmonic generation (SHG) measurements.
- Electronic bandstructure calculations.
Main Results:
- Moiré non-rigidity induces lattice relaxation (rotational reconstruction for θ<8°, volumetric dilation for θ>8°), leading to strain-mediated phonon softening and broadening.
- Selective strain localization and epitaxial-pseudomorphic patterns observed based on twist-angle.
- Davydov splitting and reduced valley polarization in MoS2 at aligned angles (0°, 60°).
- Significant enhancement in SHG (up to 480%) in WS2/WSe2 at θ-3°, and anomalous enhancement (300%) in WS2/MoSe2 at θ-60°.
Conclusions:
- The developed platforms offer programmable control over moiré superlattices in TMDs.
- Interfacial orbital interactions and strain significantly modulate interlayer coupling and optical properties.
- Findings pave the way for applications in opto-straintronics, sensing, and on-chip quantum photonics.
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