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Negative Landau Damping in Bilayer Graphene
Tiago A Morgado1, Mário G Silveirinha1,2
1Instituto de Telecomunicações and Department of Electrical Engineering, University of Coimbra, 3030-290 Coimbra, Portugal.
Physical Review Letters
|January 18, 2018
Summary
Researchers show coupled graphene sheets can generate light via a negative damping regime. Electrons drifting through the sheets trigger instabilities, leading to mid-infrared spasing for nanophotonic circuits.
Area of Science:
- Condensed Matter Physics
- Nanophotonics
- Optoelectronics
Background:
- Graphene plasmons offer unique optical properties.
- Spontaneous light emission (spasing) is desirable for on-chip light sources.
- Controlling electron drift in graphene is key to novel optoelectronic effects.
Purpose of the Study:
- To theoretically demonstrate a negative damping regime in coupled graphene sheets.
- To explore the potential for mid-infrared spasing.
- To investigate applications in nanophotonic circuitry.
Main Methods:
- Theoretical modeling of two coupled graphene sheets.
- Analysis of electron drift-induced wave instabilities.
- Investigation of plasmon pumping and spontaneous light emission.
Main Results:
- Demonstrated a negative damping regime in coupled graphene systems.
- Showcased mid-infrared spasing driven by drifting electrons.
- Established a link between drift-induced and moving media wave instabilities.
Conclusions:
- Coupled graphene sheets can act as an on-chip light source.
- The proposed structure offers wide spectral tunability and nanometer thickness.
- Potential applications in advanced nanophotonic integrated circuits.
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