title: Angular dependent anisotropic terahertz response of vertically aligned multi-walled carbon nanotube arrays with spatial dispersion.
abstract: Spatial dispersion effect of aligned carbon nanotubes (CNTs) in the terahertz (THz) region has significance for both theoretical and applied consideration due to the unique intrinsically anisotropic physical properties of CNTs. Herein, we report the angular dependent reflection of p-polarized THz wave from vertically aligned multi-walled CNT arrays in both experiment and theory. The spectra indicate that the reflection depends on the film thickness of vertically aligned CNTs, the incident angle, and the frequency. The calculation model is based on the spatial dispersion effect of aligned CNTs and performed with effective impedance method and the Maxwell-Garnett approximation. The results fit well with the experiment when the thickness of CNT film is thin, which reveals a coherent superposition mechanism of the CNT surface reflection and CNTs/Si interface reflection. For thick CNT films, the CNTs/Si interface response determines the reflection at small incident angles, while the CNTs surface effect dominates at large incident angles. This work investigates the spatial dispersion effect of vertically aligned CNT arrays in the THz region, and paves a way for potential anisotropic THz applications based on CNTs with oblique incidence requirements.
authors.affiliation: State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, School of Physics, Northwest University, Xi'an 710069, China.
authors.forename: Yixuan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Yiwen
authors.initials: Y
authors.lastname: E
authors.affiliation: State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, School of Physics, Northwest University, Xi'an 710069, China.
authors.forename: Xinlong
authors.initials: X
authors.lastname: Xu
authors.affiliation: State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, School of Physics, Northwest University, Xi'an 710069, China.
authors.forename: Weilong
authors.initials: W
authors.lastname: Li
authors.affiliation: State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, School of Physics, Northwest University, Xi'an 710069, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, School of Physics, Northwest University, Xi'an 710069, China.
authors.forename: Lipeng
authors.initials: L
authors.lastname: Zhu
authors.affiliation: State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, School of Physics, Northwest University, Xi'an 710069, China.
authors.forename: Jintao
authors.initials: J
authors.lastname: Bai
authors.affiliation: State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, School of Physics, Northwest University, Xi'an 710069, China.
authors.forename: Zhaoyu
authors.initials: Z
authors.lastname: Ren
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang