Field-effect induced tunability in hyperbolic metamaterials

Abstract

We demonstrate that use of the field effect enables tuning of the effective optical parameters of a layered hyperbolic metamaterial at optical frequencies. Field effect gating electrically modulates the permittivity in transparent conductive oxides via changes in the carrier density. These permittivity changes lead to active modulation of the effective electromagnetic parameters along with active control of the anisotropic dispersion surface of hyperbolic metamaterials and enable the opening and closing of photonic band gaps. Tunability of effective electric permittivity and magnetic permeability also leads to topological transitions in the optical dispersion characteristics. KeywordsHyperbolic metamaterials (HMM), isofrequency contour, density of optical states, epsilon near zero (ENZ), epsilon near pole (ENP), field effect, transparent conductive oxide (TCO), indium tin oxide (ITO), metal-oxide-semiconductor (MOS)

Gate-Tunable Near-Field Heat Transfer

“…The slight increase in integrated heat flux at point A, with respect to bulk SiC, in Fig. 4c, results from the large plasmonic losses (γ p ) in ITO, namely γ ITO = [200 − 263]γ SiC [41,58,59,61,62,66], for the range of carrier densities considered here. The ITO losses result in a slightlybroadened SPhP peak in spectral heat flux (dashed curve in panel (d)) with respect to bulk SiC (black curve in panel (d)), which, when integrated, results in a Q larger than Q SiC .…”

“…We model ITO with the Drude model of Eq. 4 , using m * = 0.35m e , γ p = 1.4 × 10 14 rad/s, and ∞ = 3.9 [41,59,61,62,66]. In Fig.…”

Conformal spray-deposited fluorine-doped tin oxide for mid- and long-wave infrared plasmonics

“…Transparent conductive oxides (TCOs) have been shown to be promising hosts for infrared surface plasmon polaritons (SPP). These TCOs include indium tin oxide (ITO) [1,2], aluminum-doped zinc oxide (AZO) [3,4], gallium-doped zinc oxide (GZO) [5,6], fluorinedoped tin oxide (FTO) [7,8], and antimony-doped tin oxide (ATO) [1]. Properties of SPPs on these TCOs, and localized surface plasmon resonances (LSPRs) in TCO nanoparticles have been studied, but mainly in the near-infrared (NIR).…”

“…TCO plasmonic properties can be tuned during fabrication [5,10,11] and actively postfabrication [2,4,12]. TCOs confine the infrared SPPs more tightly to the metal/dielectric interface than do typical metals.…”

Experimental demonstration of tunable graphene-polaritonic hyperbolic metamaterial

“…Due to the different sign in ε o and ε e , upon fixing the frequency ω, the isofrequency diagram of the relevant electromagnetic modes opens up into a hyperbola, giving rise to a very large density of optical states, promising for waveguiding 9 , emission engineering and Purcell enhancement 1,2,10 thermal photonics 11 , lasing 12 , and imaging 13,14 . Particularly, near the epsilon-near-zero frequency crossing of either ε o or ε e , many exciting phenomena can be supported, the most prominent of which is light propagation with near-zero phase advance 15 There has been significant effort in frequency-tuning of the optical response of hyperbolic metamaterials 6,[18][19][20] . For this, particular interest holds the case of graphene, a wellstudied monolayer material for electronics 21 and in infrared photonics 22 .…”