$\mathcal{P}\mathcal{T}$-Symmetry-Induced Wave Confinement and Guiding in Epsilon-Near-Zero Metamaterials

Abstract

Inspired by the parity-time symmetry concept, we show that a judicious spatial modulation of gain and loss in epsilon-near-zero metamaterials can induce the propagation of exponentially-bound interface modes characterized by zero attenuation. With specific reference to a bi-layer configuration, via analytical studies and parameterization 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 new possibilities for the design of optical devices and reconfigurable nanophotonics platforms.

11 pages, 8 figures. Accepted for publication in Phys. Rev. B

References in corpus (8)

• Making Sense of Non-Hermitian Hamiltonians
• PT-symmetry breaking and laser-absorber modes in optical scattering systems
• Physical realization of $\mathcal{P}\mathcal{T}$-symmetric potential scattering in a planar slab waveguide
• Experimental observation of the dual behavior of $\mathcal{P}\mathcal{T}$-symmetric scattering
• Active metamaterials: sign of refraction index and gain-assisted dispersion management
• Perfect absorption and giant magnification with a thin metamaterial layer
• Resolving the wave-vector and the refractive index from the coefficient of reflectance
• When does the choice of the refractive index of a linear, homogeneous, isotropic, active, dielectric medium matter?

Cited by in corpus (9)

• A Semi-Classical View on Epsilon-Near-Zero Resonant Tunneling Modes in Metal/Insulator/Metal Nanocavities
• Exceptional points and spectral singularities in active epsilon-near-zero plasmonic waveguides
• Realization and application of parity-time-symmetric oscillators in quantum regime
• Transmission enhancement in loss-gain multilayers by resonant suppression of reflection
• Non-Hermiticity-Induced Wave Confinement and Guiding in Loss-Gain-Loss Three-Layer Systems
• Exceptional points in parity-time symmetric plasmonic Huygens metasurfaces
• Parity-Time Symmetry and Exceptional points: A Tutorial
• Synthesizing quasi-bound states in the continuum in epsilon-near-zero layered materials
• Rigorous Quantum Formulation of Parity-Time Symmetric Coupled Resonators