Optical magnetoplasmons in rhombohedral graphite with a three-dimensional Dirac cone structure

Area of Science:

• Condensed matter physics
• Materials science

Background:

• Rhombohedral graphite possesses a 3D Dirac cone structure, closely resembling stacked graphene layers.
• This structure supports the 3D integer quantum Hall effect.

Purpose of the Study:

• To investigate optical magnetoplasmons in rhombohedral graphite.
• To demonstrate the 3D character of rhombohedral graphite through collective excitations.

Main Methods:

• Utilizing the random phase approximation to model optical magnetoplasmons.
• Analyzing Landau level mixing caused by interlayer Coulomb interactions.

Main Results:

• Optical magnetoplasmons were successfully obtained in rhombohedral graphite.
• These excitations, absent in monolayer graphene, arise from Landau level mixing in the quantum Hall regime.
• The 3D nature of rhombohedral graphite was confirmed.

Conclusions:

• The study demonstrates the 3D character of rhombohedral graphite via optical magnetoplasmons.
• These findings highlight the role of interlayer Coulomb interactions in quantum Hall physics.
• Experimental realization is expected under longitudinal electric fields or infrared radiation.