Plasmons: untangling the classical, experimental, and quantum mechanical definitions.

Area of Science:

• Condensed Matter Physics
• Nanoscience
• Quantum Mechanics

Background:

• Plasmons, collective electron oscillations, are crucial for nanoscale light manipulation in applications like spectroscopy and biosensing.
• Classical electrodynamics defines plasmons as coherent electron oscillations, a concept now extended to noble metal nanoclusters.
• Emerging quantum mechanical perspectives offer diverse criteria for identifying plasmons, leading to potential conflicts and ambiguities.

Purpose of the Study:

• To provide a comprehensive overview and clarification of plasmon definitions across different frameworks.
• To reconcile classical electrodynamics, experimental observations, and quantum mechanical criteria for plasmons.
• To identify commonalities among quantum mechanical plasmon definitions and their relation to classical and experimental views.

Main Methods:

• Review of the classical electrodynamics definition of plasmons.
• Analysis of experimental features used to identify plasmonic systems.
• Explanation and comparison of various quantum mechanical criteria for plasmons.

Main Results:

• Established connections between experimental plasmon identification and classical electrodynamics descriptions.
• Detailed exploration of quantum mechanical criteria for plasmons, revealing shared features.
• Demonstrated how quantum mechanical criteria relate to classical and experimental definitions.

Conclusions:

• A unified understanding of plasmons requires integrating classical, experimental, and quantum mechanical perspectives.
• Further research is needed to refine and expand quantum mechanical definitions for a complete plasmon theory.
• The study provides a foundation for future theoretical and experimental investigations into plasmon phenomena.