Optical Control of the Thermal Conductivity in BaTiO3

Abstract

Achieving dynamic control over thermal conductivity remains a formidable challenge in condensed matter physics and materials science, particularly due to the limitations of traditional approaches like structural modifications and doping, which yield static and often irreversible effects. In this study, a solution is demonstrated to this conundrum through light-driven manipulation of thermal conductivity in the archetypal ferroelectric BaTiO₃ (BTO). We analyze, using first-principles simulations, how photoinduced charge injection triggers a ferro-to-paraelectric phase transition, yielding ultrafast, reversible changes in thermal transport properties. These results reveal a substantial reduction in lattice thermal conductivity, especially at low photoexcited charge densities, as the material undergoes a polar-to-nonpolar transformation. This reduction is primarily due to the suppression of low-frequency phonon modes, which limits heat flow as a result of enhanced phonon–phonon scattering. These findings underscore a step forward in tunable thermal conductivity, offering new prospects for efficient thermal management in advanced electronics and energy-harvesting applications.