Current-induced local heating and extractable work in nonthermal vibrational excitation

Electron-vibration interactions in current-carrying nanodevices have been known to induce local heating and nonthermal vibration statistics simultaneously, while theoretical studies so far focus solely on one of them. Based on the quantum master equation, we study vibrationally inelastic electron transport in a double quantum dot device and find that the vibration bunching can be selectively excited for efficient charge and spin transport where the heat generation is inhibited. By introducing the nonequilibrium free energy, the extractable work under a thermal operation from nonthermal vibrations is clearly characterized and quantified. A spin transport channel with large work extraction while maintaining small heat generation rate is found. Furthermore, the extractable work is considerably enhanced by the vibration lasing transition. Our work reveals the relation between current-induced local heating and nonthermal vibration statistics and effects on extractable work, with the aim to control the distribution, storage, and conversion of the heat in nanodevices.