Tunable Hyperbolic Metamaterials Based on Self-Assembled Carbon Nanotubes

Abstract

We show that packed, horizontally aligned films of single-walled carbon nanotubes are hyperbolic metamaterials with ultra-subwavelength unit cells and dynamic tunability. Using Mueller-matrix ellipsometry, we characterize the films' doping-level dependent optical properties and find a broadband hyperbolic region tunable in the mid-infrared. To characterize the dispersion of in-plane hyperbolic plasmon modes, we etch the nanotube films into nanoribbons with differing widths and orientations relative to the nanotube axis, and we observe that the hyperbolic modes support strong light localization. Agreement between the experiments and theoretical models using the ellipsometry data indicates that the packed carbon nanotubes support bulk anisotropic responses at the nanoscale. Self-assembled films of carbon nanotubes are well suited for applications in thermal emission and photodetection, and they serve as model systems for studying light-matter interactions in the deep subwavelength regime.

References in corpus (11)

• Topological Transitions in Metamaterials
• Tunable light-matter interaction and the role of hyperbolicity in graphene-hBN system
• Surface plasmon Fourier optics
• Purcell effect in Hyperbolic Metamaterial Resonators
• Strong exciton-plasmon coupling in semiconducting carbon nanotubes
• Science and applications of wafer-scale crystalline carbon nanotube films prepared through controlled vacuum filtration
• Strong and broadly tunable plasmon resonances in thick films of aligned carbon nanotubes
• Coherent plasmon and phonon-plasmon resonances in carbon nanotubes
• Intrinsically ultrastrong plasmon-exciton interactions in crystallized films of carbon nanotubes
• An ultra-broadband electromagnetically indefinite medium formed by aligned carbon nanotubes
• Single wall carbon nanotubes as coherent plasmon generators