Electronic and Phononic Thermal Conduction in Materials with Metal-Insulator Phase Transitions

Metal-insulator phase transition (MIT) occurs in a wide range of materials with diverse mechanisms, such as the Mott and Peierls transitions. In contrast to existing in-depth investigations of electrical conduction across the MIT, thermal conduction of these materials has been relatively less explored owing to difficulties in accurate measurements and the high sensitivity of heat conduction to materials quality and configuration. However, exploration of electrons and phonons carried thermal conduction across the MIT is much needed because it would provide unique and deep insight into the phase transition physics and charge dynamics of the materials. In this invited talk, we will discuss our recent results in measurements and analysis of thermal conductivity of high-quality, single-crystal nanowire/nanoribbon of materials with MIT, including doped VO₂ whose MIT is believed to have a coupled Mott-Peierls nature, and TaS₂ and TaS₃ that are typical charge density wave materials.