Description of the thesis topic

This PhD thesis aims to develop a conductive thermal diode driven by the heat generated by surface electromagnetic waves (polaritons) propagating along the surface of polar nanowires with a metallic coating. Experimental data show that this coating acts as a polariton launcher and hence its presence at one of the nanowire ends only, is expected to generate an efficient rectification of conductive heat currents. Based on the Maxwell equations of electromagnetism, the Boltzmann transport equation, and the fluctuational electrodynamics, theoretical calculations will be done to quantify and optimize this rectification effect for nanowires of SiO2, SiC, and SiN with a gold coating at one of their ends. The optimized material configurations will be used to experimentally measure the axial thermal conductivity of the nanowires supporting the propagation of heat in both the forward and backward directions. These measurements will be done using the well-established thermal bridge method and will allow us to determine the rectification efficiency of the proposed polariton thermal diode. The obtained results could confirm that polaritons are effective heat carriers able to rectify heat currents and improve heat dissipation from electronic components every time thinner.

Work Context

The thesis will be developed within the Institut des NanoSciences de Paris, a joint research unit (UMR 7588) of the CNRS and Sorbonne University.