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Updated: Jan 18, 2026
07:39
Determination of the Excitation and Coupling Rates Between Light Emitters and Surface Plasmon Polaritons
Published on: July 21, 2018
7.2K
Intrinsically undamped plasmon modes in narrow electron bands
Cyprian Lewandowski1, Leonid Levitov2
1Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 cyprian@mit.edu.
Summary
Landau damping is quenched in narrow-band 2D electron systems due to strong coupling. This leads to undamped surface plasmons, enhancing optical coherence and observable via speckle interference.
Area of Science:
- Condensed matter physics
- Materials science
Background:
- Surface plasmons in 2D electron systems are typically subject to Landau damping.
- Landau damping involves dissipation through electron-hole pair excitation.
- Narrow Bloch bands and strong coupling can alter plasmon behavior.
Purpose of the Study:
- To investigate the regime where Landau damping is completely quenched in 2D electron systems.
- To explore the role of strong coupling and narrow bands in dissipation quenching.
- To identify potential material systems and experimental signatures for this phenomenon.
Main Methods:
- Theoretical analysis of surface plasmons in narrow-band 2D electron systems.
- Investigation of the conditions for plasmon modes to exit the particle-hole continuum.
- Focus on systems with a large "fine structure" constant, such as moiré graphene at magic twist angles.
Main Results:
- Complete quenching of Landau damping is predicted under specific conditions.
- Dissipation is suppressed when plasmon modes enter the energy gap above the particle-hole continuum.
- Moiré graphene with flat bands at magic twist angles is a promising candidate system.
- Extinction of Landau damping leads to enhanced spatial optical coherence.
Conclusions:
- Landau damping can be effectively quenched in narrow-band 2D electron systems with strong coupling.
- This phenomenon is particularly relevant for moiré graphene.
- Speckle-like interference patterns in near-field imaging can serve as experimental evidence for undamped plasmons.
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