Fig. 5
From: Hyperbolic metamaterials: fusing artificial structures to natural 2D materials
a, b Adapted with permission from ref. [27], copyright 2019, NPG. c Adapted with permission from ref. [122], copyright 2018, WILEY. d Adapted with permission from ref. [123], copyright 2014, OSA
Negative refraction using vertical and switchable HMMs. a Effective permittivity in horizontally-stacked multilayered HMMs (hHMMs) and vertically-stacked multilayered HMM (vHMMs), and b intensity profiles in hHMMs and vHMMs composed of aluminum (Al) and \({\text {SiO}_2}\). Green arrows: Poynting vectors. c Switchable refraction between negative to positive using layers of phase change materials (PCM). Dashed lines: HMM; arrows: power flow for transverse magnetic (TM) polarized light. d Switchable refraction from negative to positive and reflection, using liquid crystal HMMs.