Optical beam shifts in graphene and single-layer boron-nitride

Area of Science:

• Physics
• Materials Science
• Optics

Background:

• Freestanding 2D atomic crystals exhibit unique optical properties.
• Understanding optical beam shifts is crucial for applications in nanophotonics.

Purpose of the Study:

• Investigate optical beam shifts, specifically the Goos-Hänchen and Imbert-Fedorov shifts, in freestanding 2D atomic crystals.
• Compare the behavior of these shifts in 2D crystals with their counterparts in 3D crystals.

Main Methods:

• Theoretical analysis of optical beam shifts using Fresnel equations.
• Modeling the interaction of light with a freestanding 2D atomic crystal surface.

Main Results:

• The Goos-Hänchen shift magnitude in 2D crystals is determined by surface susceptibility, independent of incident light wavelength.
• Surface conductivity plays a minor, second-order role in the optical beam shifts.
• The Imbert-Fedorov shift and angular shifts depend on wavelength and beam angular aperture, respectively, similar to 3D crystals.

Conclusions:

• Optical beam shifts in 2D atomic crystals are governed by distinct physical mechanisms compared to bulk materials.
• Surface susceptibility is the dominant factor for the Goos-Hänchen shift in 2D systems.
• These findings have implications for designing optical devices utilizing 2D materials.