A phononic switch based on ferroelectric domain walls

Abstract

The ease with which domain walls (DWs) in ferroelectric materials can be written and erased provides a versatile way to dynamically modulate heat fluxes. In this Rapid Communication we evaluate the thermal boundary resistance (TBR) of ${180}^{\ensuremath{\circ}}$ DWs in the prototype ferroelectric perovskite ${\mathrm{PbTiO}}_{3}$ within the numerical formalisms of nonequilibrium molecular dynamics and nonequilibrium Green's functions. An excellent agreement is obtained for the TBR of an isolated DW derived from both approaches, which reveals the harmonic character of the phonon-DW scattering mechanism. The thermal resistance of the ferroelectric material is shown to increase up to around 20%, in the system sizes considered here, due to the presence of a single DW, and larger resistances can be attained by the incorporation of more DWs along the path of thermal flux. These results, obtained at device operation temperatures, prove the viability of an electrically actuated phononic switch based on ferroelectric DWs.