Fluctuational electrodynamics of hyperbolic metamaterials

Abstract

We give a detailed account of equilibrium and non-equilibrium fluctuational electrodynamics of hyperbolic metamaterials. We show the unifying aspects of two different approaches; one utilizes the second kind of fluctuation dissipation theorem and the other makes use of the scattering method. We analyze the near-field of hyperbolic media at finite temperatures and show that the lack of spatial coherence can be attributed to the multi-modal nature of super-Planckian thermal emission. We also adopt the analysis to phonon-polaritonic super-lattice metamaterials and describe the regimes suitable for experimental verification of our predicted effects. The results reveal that far-field thermal emission spectra are dominated by epsilon-near-zero and epsilon-near-pole responses as expected from Kirchoff's laws. Our work should aid both theorists and experimentalists to study complex media and engineer equilibrium and non-equilibrium fluctuations for applications in thermal photonics.Comment: 13 pages, 8 figure

Nonequilibrium atom-surface interaction with lossy multilayer structures

“…4), while previous work [46] has shown that the expressions in Eqs. (21) are only compatible with βd sl 1. In both plots, we can see that for ω < γ the EMA description enters the sub-ohmic regime discussed above.…”

“…where f = d A /d sl gives the filling factor of material A. Equations (21) correspond to the propagation of the electromagnetic field parallel ( ) or orthogonal ( ⊥ ) to the optical axis of the crystal, in our case the z-axis.…”

“…This quantum frictional force is affected by the appearance of electromagnetic resonances due to the inter-layer interaction of plasmon-polaritons at the dielectricmetal interfaces and can be tailored by acting on the geometry and the material properties of the individual layers. 21]. When carefully designed, they are known for exhibiting effective hyperbolic dispersion relations [20,22,23], which have applications in many fields of research [24][25][26].…”

Near-Field Heat Transfer between Multilayer Hyperbolic Metamaterials

“…Furthermore, it has been shown that HM can be used for near-field thermophotovoltaic applications [51,52], which HM have a large penetration depth of thermal radiation [53,54], which is an advantage also for the transport of near-field thermal radiation over far-field distances [55]. In addition, the possibility of having larger conduction by thermal radiation inside an HM than conduction by phonons and electrons has been discussed [56] as well as the thermodynamical potentials, the general laws of thermal radiation inside HM [57] and the coherence properties in the vicinity of HM [58]. Recently, also tunable hyperbolic thermal emitters have been introduced [59], and it was proposed to make the use of the hyperbolic 2D plasmons in graphene ribbons for elevated near-field heat fluxes [60].…”

Many-body heat radiation and heat transfer in the presence of a nonabsorbing background medium

“…Despite the generality of the available theories, a closed-form expression for the heat transfer between three objects in vacuum has only recently been given [17], and has already provided several interesting applications to heat transfer amplification [33] and guiding [34]. Aside from the advances in general formalism, various applications have been investigated in recent nonequilibrium studies [35][36][37][38][39][40][41][42][43]. On the experimental side, the development of high-precision measurement devices has verified many theoretical predictions concerning radiative heat transfer [44][45][46][47][48][49].…”