Mechanism analysis and optimization of dynamic functional response of nanoscale thermal cloak

Abstract

In recent years, with the booming development of nanodevices and technologies, the nanoscale thermal cloak has gradually attracted researchers’ interest due to its unique way of utilizing heat energy. However, most existing studies only restrictively place the nanoscale thermal cloak in a constant external environment but neglect the study of its performance under dynamic conditions, which results in insufficient understanding and limits the application scope of this functional structure. Therefore, in this paper, we design a nanoscale thermal cloak and explore functional response in a triangular waveform-based dynamic temperature, in which temperature peak and change period are set as variables. The results show that the nanoscale thermal cloak performs well in three different dynamic environments and that the larger the amorphous ring width, the smaller the temperature peak, and the larger the variation period, the better the cloaking effect. Furthermore, we propose to use the response temperature to quantify the disturbance of the cloak's presence in the external environment. The smaller the amorphous ring width, the smaller the disturbance to the external temperature. When the ring width is fixed, the temperature peak is smaller, the variation period is longer, and the external temperature disturbance is smaller. Finally, we use phonon localization theory to explain the underlying mechanism. By calculating and analyzing the phonon density of states (PDOS) and mode participation rate (MPR), we find that phonon localization in the functional region is the main reason for the cloaking phenomenon. In addition, we plot the spatial distribution information of phonon localization to visualize the phenomenon of localization. This study expands the application scope of the nanoscale thermal cloak and can provide a reference for the development of other nanoscale devices.