Near-field-driven Radiative Thermal Dynamics in Aperiodic Nanostructures

TL;DR

The paper addresses how deterministic aperiodic order shapes near-field radiative heat transfer in ensembles of polaritonic nanoparticles. It uses Vogel spirals to tunably interpolate between periodic and random layouts and employs a dipole-based, fluctuational-electrodynamics framework with an eigenmode decomposition to capture multi-body coupling. The main finding is that increasing structural disorder slows thermalization, with the divergence angle providing a continuous control over transient energy transport; GA-like order yields fastest equilibration while more irregular spirals slow it, and random configurations do not surpass the best aperiodic designs. This approach offers a design principle for dynamic thermal nanophotonics, enabling predictive control of energy flow at the nanoscale and informing fabrication tolerances for practical implementations. The work thus bridges deterministic aperiodic photonics with near-field thermal management, highlighting the potential of Vogel spirals for tailoring radiative heat transfer dynamics in nanostructured devices.

Abstract

Harnessing structural correlations in near-field plasmonic and polaritonic systems hold untapped potential for controlling light-matter interactions at the nanoscale. By tuning these correlations, one can reshape mode localization, coupling, and spectral distribution which are properties central to manipulating energy transport and field enhancement in nanophotonic platforms. We exploit Vogel spirals, an aperiodic geometry where a single parameter dictates spatial correlations, to show how correlation strength reshapes the modal spectrum and transient dynamics of near-field coupling. As a proof of concept, we demonstrate that aperiodic configurations outperform both uncorrelated (random) and periodic arrays in controlling near-field radiative heat-transfer dynamics. These results establish deterministic aperiodic order as a powerful platform for tailoring correlated electromagnetic responses in next-generation nanophotonic devices.

Figures (6)

• Figure 1: Schematic representation of thermalization dynamics in two Voguel spirals where the center particle is initially at a higher temperature than all others in the array.
• Figure 2: Thermalization dynamics for a square array of $N = 1024$ SiC nanoparticles with radius $R = 25\,$nm and interparticle distance $d_1$, under different initial conditions. Colored curves show the time evolution of the temperature of the selected nanoparticle that begins at $\Delta T = 50\,$K while all others are initially in thermal equilibrium with the environment at $T_0 = 300\,$K. The inset shows the position of the initial hot particles: blue (red) represents the closest (farthest) point from the geometrical center of the array, and the green point is at the median distance. The gray curve corresponds to the case where all nanoparticles are initially at $\Delta T = 50/1024\,$K and the arrow indicates the interparticle thermalization time $t_\mathrm{Th}$ for the initial condition depicted in blue with $d_1 = 5R$.
• Figure 3: (a) Schematic representation of the different Vogel spirals under consideration. (b-e) Distribution of the interparticle distances for the GA (b), $\tau$ (c), $\mu$ (d), and $\pi$ (e) spirals, respectively. Orange and blue dots correspond to the systems with $N=100$ and $N=1024$ nanoparticles, respectively. (f) Standard deviation of the interparticle distances for the Vogel spirals in (b)-(e).
• Figure 4: Thermalization dynamics for the GA (a), $\tau$ (b), $\mu$ (c), and $\pi$ (d) spirals with $\langle d_1 \rangle = 5R$, under the same conditions as in Fig. \ref{['fig:square']}. Insets show the corresponding spiral geometries.
• Figure 5: Thermalization dynamics for two random arrays of $N=1024$ nanoparticles with constrained $d_\mathrm{min} = 4R$ and $\langle d_1 \rangle = 5R$, under the same conditions as in Fig. \ref{['fig:square']}. Panels (a) and (b) show the fastest and slowest realizations, respectively. Insets show the corresponding geometries.