Exploiting the Momentum Distribution in Atomically Confined Plasmonic Fields by Inelastic Scatterings

Area of Science:

• Condensed Matter Physics
• Nanophotonics
• Materials Science

Background:

• Atomically confined plasmonic fields have advanced imaging techniques.
• The position-momentum uncertainty principle implies broad momentum distribution in confined fields, a factor often overlooked.
• Measuring phonon dispersions is crucial for understanding material properties.

Purpose of the Study:

• To propose a novel method for exploiting momentum distribution in confined plasmonic fields.
• To develop an optical technique for directly measuring complete phonon dispersions.
• To enable the study of phonon dispersions in low-dimensional, hydrogen-rich materials inaccessible by other methods.

Main Methods:

• Utilizing inelastic Raman scattering in periodic systems.
• Adaptively satisfying the conservation law of momentum.
• Analyzing Raman images to extract phonon dispersion information.

Main Results:

• Demonstrated the ability to conclusively measure all phonon dispersion branches for the first time.
• Numerical results for an all-trans polyacetylene chain validated the technique.
• Showcased the technique's effectiveness for low-dimensional materials.

Conclusions:

• The proposed method offers a unique optical approach to measure phonon dispersions.
• This technique overcomes previous limitations in studying specific material types.
• Highlights the potential of momentum-based nanophotonics and confined plasmonic fields.