Nonreciprocal plasmons in one-dimensional carbon nanostructures.

Area of Science:

• Plasmonics
• Nanophotonics
• Condensed Matter Physics

Background:

• Miniaturized plasmonic waveguides offer potential for nanophotonic technologies.
• Conventional plasmonic materials have reciprocal optical responses, hindering directional light control.
• Graphene's high electrical current capacity suggests promise for nonreciprocal plasmonics, but studies are limited to linear electrical dispersion.

Purpose of the Study:

• To theoretically investigate quantum finite-size and nonlocal effects in the nonreciprocal response of mesoscale plasmonic waveguides.
• To explore the use of drift-biased graphene nanoribbons (GNRs) and carbon nanotubes (CNTs) for nonreciprocal plasmonics.
• To demonstrate active control of guided plasmon modes through electrical bias.

Main Methods:

• Atomistic simulation methods utilizing tight-binding electronic states.
• Self-consistent quantum mean-field optical response calculations.
• Theoretical exploration of quantum finite-size and nonlocal effects.

Main Results:

• A moderate electrical bias can significantly break reciprocity for guided plasmon mode propagation in GNRs and CNTs with electronic band gaps.
• The applied current allows active control over the excitation and propagation of guided plasmon modes.
• Nonlocal interactions between multiple emitters can be mediated by the plasmon modes.

Conclusions:

• Graphene nanostructures provide a promising atomically thin platform for achieving nonreciprocal nanophotonics.
• Electrical bias in GNRs and CNTs can be used to engineer nonreciprocal light control.
• This work opens avenues for advanced nanophotonic devices with directional light manipulation.