Abstract
Inspired by the parity-time symmetry concept, we show that a judicious spatial modulation of gain and loss in -near-zero metamaterials can induce the propagation of exponentially bound interface modes characterized by zero attenuation. With specific reference to a bilayer configuration, via analytical studies and parametrization of the dispersion equation, we show that this waveguiding mechanism can be sustained in the presence of moderate gain/loss levels, and it becomes leaky (i.e., radiative) below a gain/loss threshold. Moreover, we explore a possible rod-based metamaterial implementation, based on realistic material constituents, which captures the essential features of the waveguiding mechanism, in good agreement with our theoretical predictions. Our results may open up possibilities for the design of optical devices and reconfigurable nanophotonics platforms.
1 More- Received 30 September 2014
- Revised 18 February 2015
DOI:https://doi.org/10.1103/PhysRevB.91.115114
©2015 American Physical Society