Energy band structure of multistream quantum electron system

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics
• Plasma Physics

Background:

• Plasmonic excitations in electron gases are crucial for understanding material properties.
• Previous models often simplify electron interactions, limiting accuracy for degenerate systems.

Purpose of the Study:

• To develop a quantum multistream model for studying electronic band structure in plasmonic excitations.
• To investigate the origins of energy band gaps in streaming electron gas.
• To explore the influence of virtual streams and collective interactions on plasmonic band structures.

Main Methods:

• Utilizing a multifluid quantum hydrodynamic model to derive N-coupled pseudoforce differential equations.
• Calculating the energy band structure of plasmonic excitations from these equations.
• Generalizing the quantum multistream model to include virtual streams for 1D plasmonic crystals.

Main Results:

• Demonstrated that discrete velocity filaments and electrostatic mode coupling lead to energy bands separated by gaps.
• Provided an alternative description for collisionless damping and phase mixing within energy band gaps.
• Showed that energy band gaps in plasmon excitations arise from collective electrostatic interactions, unlike free electron models.
• Identified that plasmonic band gap size at the Brillouin zone boundary maximizes near metallic densities.

Conclusions:

• The formation of energy band structure is a general characteristic of coupled quantum multistream systems.
• The quantum multistream model offers a comprehensive approach to understanding plasmonic excitations and their band structures.
• The findings have implications for designing materials with specific electronic and optical properties.