Tunable surface plasmon instability leading to emission of radiation
Abstract
We propose a new approach for energy conversion from a dc electric field to tunable terahertz emission based on hybrid semiconductors by combining two-dimensional (2D) crystalline layers and a thick conducting material with possible applications for chemical analysis, security scanning, medical (single-molecule) imaging, and telecommunications. The hybrid nano-structure may consist of a single or pair of sheets of graphene, silicene, or a 2D electron gas. When an electric current is passed through a 2D layer, we discover that two low-energy plasmon branches exhibit a characteristic loop in their dispersion before they merge into an unstable region beyond a critical wave vector qc. This finite qc gives rise to a wavenumber cutoff in the emission dispersion of the surface plasmon induced instability and emission of radiation (spiler). However, there is no instability for a single driven layer far from the conductor, and the instability of an isolated pair of 2D layers occurs without a wavenumber cutoff. The wavenumber cutoff is found to depend on the conductor electron density, layer separation, distances of layers from the conductor surface, and the driving-current strength.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 04, 2015
- Source ID
- 10.1063/1.4927101
Entities
People
- Andrii Iurov
- Danhong Huang
- Godfrey Gumbs
- Wei Pan
Organizations
- Air Force Research Laboratory
- City University of New York
- Donostia International Physics Center
- Sandia National Laboratories
- University of New Mexico