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Nonlinear Tunable Vibrational Response in Hexagonal Boron Nitride.
Fadil Iyikanat1, Andrea Konečná1, F Javier García de Abajo1,2
1ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860 Barcelona, Spain.
ACS Nano
|July 26, 2021
Summary
Hexagonal boron nitride (hBN) exhibits a strong nonlinear optical response in the mid-infrared due to atomic vibrations. This enables new applications in optoelectronics and photonics.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Photonics
Background:
- Nonlinear light-matter interactions are crucial for photonics but typically require high optical intensities.
- Structured materials offer unique properties, yet achieving significant nonlinear effects at the nanoscale remains challenging.
Purpose of the Study:
- To investigate the nonlinear optical response of monolayer hexagonal boron nitride (hBN) in the mid-infrared phonon-polariton region.
- To explore the potential of hBN for advanced photonic applications and electrical tunability.
Main Methods:
- First-principles theory calculations to predict nonlinear effects.
- Analysis of atomic vibrations, phonon lifetimes, and configuration energy landscapes.
- Investigation of interactions between static and optical fields.
Main Results:
- Monolayer hBN shows a large nonlinear response, with a threshold light field of ~24 MV/m for significant Kerr nonlinearities and harmonic generation.
- Long phonon lifetimes and asymmetric energy landscapes in hBN contribute to this strong response.
- Electrical tuning of optical phonon modes is predicted using in-plane DC fields, exceeding phonon spectral width.
Conclusions:
- Monolayer hBN possesses a strong nonlinear response in the mid-infrared, driven by anharmonic atomic vibrations.
- This material enables polariton blockade and offers a practical scheme for electrical tunability of vibrational modes.
- hBN polaritons are promising for mid-infrared optoelectronics, light modulation, sensing, and metrology.
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