Control of the Radiative Heat Transfer in a Pair of Rotating Nanostructures

The fluctuations of the electromagnetic field are at the origin of the near-field radiative heat transfer between nanostructures, as well as the Casimir forces and torques that they exert on each other. Here, working within the formalism of fluctuational electrodynamics, we investigate the simultaneous transfer of energy and angular momentum in a pair of rotating nanostructures. We demonstrate that, due to the rotation of the nanostructures, the radiative heat transfer between them can be increased, decreased, or even reversed with respect to the transfer that occurs in the absence of rotation, which is solely determined by the difference in the temperature of the nanostructures. This work unravels the unintuitive phenomena arising from the simultaneous transfer of energy and angular momentum in pairs of rotating nanostructures.

Figure 1

The system under study consists of two axially symmetric nanostructures separated by a distance $l$ along the $z$ axis. The nanostructures have dimensions $D_1$, $d_1$ and $D_2$, $d_2$, are at temperatures $T_1$ and $T_2$, and rotate with frequencies ${\mathrm{\Omega }}_1$ and ${\mathrm{\Omega }}_2$. The temperature of the environment is $T_0$.

Figure 2

Effective temperature ratio $\xi$ for two nanostructures rotating with different frequencies. The dashed lines indicate the values of ${\mathrm{\Omega }}_1$ and ${\mathrm{\Omega }}_2$ for which the ratio is equal to one.

Figure 3

Power transferred between two rotating nanostructures normalized to ${\mathrm{\Pi }}_1$ for ${\theta }_1=1.5{\theta }_2$. The black solid and dashed curves signal $P_1/{\mathrm{\Pi }}_1=0$ and $P_1/{\mathrm{\Pi }}_1=1$, respectively, while the labels indicate the regimes in which $P_1/{\mathrm{\Pi }}_1>1$ (i), $0<P_1/{\mathrm{\Pi }}_1<1$ (ii), and $P_1/{\mathrm{\Pi }}_1<0$ (iii).

Figure 4

Power transferred (black curve) and rates of change in mechanical energy (blue curves) and internal energy (red curves) for nanostructure 1 (solid curves) and 2 (dashed curves). All quantities are normalized to $|{\mathrm{\Pi }}_1|$. We assume ${\mathrm{\Omega }}_1=0.5{\theta }_2$ and ${\theta }_1=1.5{\theta }_2$. Regions of negative (positive) $P_1$ are indicated with a purple (green) background.