Intrinsically undamped plasmon modes in narrow electron bands
Abstract
We argue that moiré graphene provides an opportunity to realize plasmons not subject to Landau damping. Eliminating damping is central for the ongoing quest for low-loss plasmons and dissipationless light–matter coupling. “Lifting the curse” of Landau dissipation is a surprising behavior originating from plasmon modes extending far above the narrow-band particle–hole continuum into the forbidden energy gap, where they decouple from particle–hole excitations. While our findings apply broadly to all narrow electron bands with an energy gap above the flat band, these effects are particularly prominent in moiré graphene because of uniquely strong electron interactions in this material. The intrinsically undamped plasmons feature enhanced optical coherence and spatial interference, directly testable by state-of-the-art near-field techniques.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 27, 2019
- Source ID
- 10.1073/pnas.1909069116
Entities
People
- Cyprian Lewandowski
- Leonid Levitov
Organizations
- Army Research Office
- Division of Materials Research
- Massachusetts Institute of Technology