Resonant edge magnetoplasmons and their decay in graphene

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Edge magnetoplasmons (EMPs) are charge-carrier collective excitations confined to the edges of 2D electron systems.
• Graphene's unique electronic properties, including its linear band structure and sharp edge potential, make it a promising platform for studying EMPs.
• Understanding EMP behavior is crucial for developing novel electronic and spintronic devices.

Purpose of the Study:

• To investigate the resonant edge magnetoplasmons (EMPs) and their decay mechanisms in graphene.
• To determine the dispersion relation of EMPs in disk-shaped graphene structures.
• To differentiate between intrinsic and extrinsic dissipation processes affecting EMPs in graphene.

Main Methods:

• High-frequency electronic measurements were employed to probe EMP resonances.
• Analysis of EMP resonance frequencies and decay times in disk-shaped graphene.
• Comparison of EMP dissipation in graphene with that in traditional materials like GaAs.

Main Results:

• Nonlinear dispersion relation for EMPs in graphene was observed, attributed to interactions.
• Intrinsic decay of EMP wave packets was identified as a consequence of the nonlinear dispersion.
• Extrinsic dissipation mechanisms, linked to localized states in bulk graphene, were distinguished from intrinsic decay.

Conclusions:

• Graphene exhibits intrinsic EMP decay due to its nonlinear dispersion relation.
• Localized states in graphene contribute to extrinsic EMP dissipation.
• Graphene offers potentially lower EMP dissipation compared to GaAs systems, owing to its unique electronic and edge properties.