Interference-Controlled Radiative Heat Transport in Time-Modulated Networks

Abstract

We demonstrate photonic control of radiative heat transport in nanoscale networks through phase-controlled interference between elastic and inelastic Floquet scattering channels induced by temporal permittivity modulation. Relative modulation phases select constructive or destructive interference, enabling directional thermal-photon currents and heat splitting even at thermal equilibrium. Modulation amplitude and frequency further tune the enhancement, suppression and redistribution of energy flow. This interference-based mechanism enables thermal routing and logic operations and provides a general platform for reconfigurable photonic heat management at the nanoscale.

Figures (4)

• Figure 1: Out of equilibrium energy exchange between a SiC and a GaN particle ($R=50\: nm$ radius) separated by a distance $d=3R$ when $T_{SiC}=400\,$K and $T_{GaN}=300\,$K and the particle polarizabilities undergoe a harmonic modulation with a dephasing $\Delta \phi=\{0,\pi/2,-\pi/2\}$ in Figs (a), (b) and (c), respectively. The SiC and GaN permittivities are modeled by a Lorentz oscillator Palik, $\varepsilon(\omega) = \varepsilon_\infty (\omega_{\rm LO}^2 - \omega^2 - i\gamma \omega)/(\omega_{\rm TO}^2 - \omega^2 - i\gamma \omega)$, with parameters $\varepsilon_\infty = 6.7$, $\omega_{\rm LO}= 1.825\times10^{14}$ rad/s, $\omega_{\rm TO} = 1.494\times10^{14}$ rad/s, $\gamma = 8.966\times10^{11}$ rad/s for SiC, and $\varepsilon_\infty = 5.35$, $\omega_{\rm LO}= 1.415\times10^{14}$ rad/s, $\omega_{\rm TO} = 1.315\times10^{14}$ rad/s, $\gamma = 1.0\times10^{12}$ rad/s for GaN. The modulation frequency $\Omega=\Delta\omega_{\rm LO}$. The difference in arrow thickness between the particles indicates the relative importance of elastic (red) and inelastic (green) transport processes. Inset: total and inelastic energy exchanged in linear scale.
• Figure 2: Directional energy exchange between two SiC nanoparticles at the same temperature $T=350\:K$ under a harmonic modulation (a) $\Omega=\omega_{\rm LO}^{(\mathrm{SiC})}-\omega_{\rm TO}^{(\mathrm{SiC})}$ of particles polarizability with a phase shift $\Delta\phi\equiv\phi_2-\phi_1=\pm \pi/2$. (b) Harmonic modulation at two different frequencies with a phase shift $\Delta\phi= \pi/2$. Same geometrical and physical parameter as in Fig.1.Inset: direction of heat flux (equal to 1 (resp. -1), when the flux is in direction of particle 2 (resp. 1)).
• Figure 3: Phase-controlled splitting of radiative heat flux. Splitting ratio $R^{1\to 2}$, defined from the net absorbed power, in a three-nanoparticle SiC--GaN--GaN network with $\delta\alpha=0.1$. The SiC nanoparticle (red) acts as a hot source at $T_1=400\,\mathrm{K}$, while the two GaN nanoparticles (blue) serve as colder outputs held at $T_2=T_3=300\,\mathrm{K}$. Panels (a) and (b) correspond to relative modulation phases $\Delta\phi=+\pi/2$ and $\Delta\phi=-\pi/2$, respectively. The GaN output nanoparticles are harmonically modulated at the frequency $\Omega=\omega_{\mathrm{LO}}^{(\mathrm{GaN})}-\omega_{\mathrm{TO}}^{(\mathrm{GaN})}$ with $\delta\alpha=0.1$.
• Figure 4: Phase-controlled splitting of radiative heat flux in a three-nanoparticle SiC--InSb--InSb network for a relative modulation phase $\Delta\phi=\pm\pi/2$. The SiC nanoparticle (red) acts as a hot source at $T_1=400\,\mathrm{K}$, while the two InSb nanoparticles (blue) serve as colder outputs at $T_2=T_3=300\,\mathrm{K}$. The InSb nanoparticles are harmonically modulated at a low frequency $\Omega=10^{10}\,\mathrm{rad\,s^{-1}}$ with a modulation amplitude $\delta\alpha=0.2$, which can be experimentally realized via piezoelectric actuation. The dielectric response of InSb is described by a Lorentz model Palik with parameters $\varepsilon_\infty=15.7$, $\omega_\mathrm{LO}=3.62\times10^{12}\,\mathrm{rad/s}$, $\omega_\mathrm{TO}=3.39\times10^{12}\,\mathrm{rad/s}$ and damping $\gamma=5.65\times10^{10}\,\mathrm{rad/s}$.The chosen modulation parameters correspond to conditions that can be experimentally realized via piezoelectric actuation.