Coulomb-mediated single-electron heat transfer statistics across capacitively coupled silicon nanodots

Heat transfer mediated by the Coulomb interaction reveals unconventional thermodynamic behavior and broadens thermodynamics research into fields such as quantum dynamics and information engineering. Although some experimental demonstrations of phenomena utilizing Coulomb-mediated heat transfer have been reported, estimations of their performance, such as efficiency, and their theoretical evaluations necessitate qualitative evaluation of the transfer mechanism itself, which remains challenging. We present an experiment investigating single-electron dynamics in two electrostatically coupled silicon nanodots to quantify Coulomb-mediated heat transfer at the nanoscale. By estimating the Coulomb interaction strength between the dots using the cross-correlation measurements of the single-electron dynamics, we convert the single-electron dynamics into the statistics of Coulomb-mediated heat transfer. Conducting the experiment at equilibrium enabled us to obtain a fluctuating net-zero heat transfer between the dots. These heat transfer statistics are essential for exploring device functionalities from the perspective of stochastic thermodynamics and for verifying universal relations in nonequilibrium states. Coulomb-mediated energy transfer enables the separation of heat and charge currents and the realization of unconventional heat-engine operations, including information heat engines. The authors quantify the statistics of Coulomb-mediated heat transfer across electrostatically coupled silicon nanodots from single-electron dynamics, providing a basis for exploring these unconventional heat engines within the framework of stochastic and quantum thermodynamics.