Negative Effective Mass in Plasmonic Systems
Abstract
We report the negative effective mass (density) metamaterials based on the electro-mechanical coupling exploiting plasma oscillations of a free electron gas. The negative mass appears as a result of the vibration of a metallic particle with a frequency of ω, which is close the frequency of the plasma oscillations of the electron gas m2 relative to the ionic lattice m1. The plasma oscillations are represented with the elastic spring k2=ωp2m2, where ωp is the plasma frequency. Thus, the metallic particle vibrated with the external frequency ω is described by the effective mass meff=m1+m2ωp2ωp2‑ω2, which is negative when the frequency ω approaches ωp from above. The idea is exemplified with two conducting metals, namely Au and Li.
- Publication:
-
Materials
- Pub Date:
- April 2020
- DOI:
- 10.3390/ma13081890
- Bibcode:
- 2020Mate...13.1890B
- Keywords:
-
- metamaterials;
- negative effective mass;
- plasma oscillations;
- low frequency plasmons