Non-Monotonic Thermoelectric Currents and Energy Harvesting in Interacting Double Quantum-Dots

TL;DR

This theoretical study investigates how interactions in double quantum dots cause non-monotonic thermoelectric currents, affecting energy harvesting capabilities and revealing conditions for optimal thermoelectric energy conversion.

Contribution

It introduces a rate-equation approach to analyze interaction-induced non-monotonic thermoelectric currents in double quantum dots, highlighting their impact on energy harvesting.

Findings

Interactions cause non-monotonic dependence of current on thermal bias.

Energy harvesting is possible only under specific configurations.

Optimal conditions for thermoelectric energy conversion are identified.

Abstract

A theoretical study of the thermoelectric current and energy harvesting in an interacting double quantum dot system, connected to reservoirs held at different chemical potentials and temperatures is presented. Using a rate-equation approach, the current is evaluated for different energetic configurations of the double quantum dot. We discuss in detail the current-temperature gradient relations (the thermoelectric analog to current-voltage relations), and demonstrate that, due to interactions, the current is non-monotonically dependent on thermal bias. This interaction-induced non-monotonicity influences the possibility of harvesting thermal energy from the double-quantum dot, and it is shown that in some configurations, energy cannot be harvested at all. We analyze the conditions under which energy can indeed be harvested and converted to useful electrical power, and the optimal conditions for thermoelectric energy conversion.