Enhanced performance of a quantum-dot-based nanomotor due to Coulomb interactions

TL;DR

This paper investigates how Coulomb interactions enhance the efficiency and shift the resonance in a quantum-dot-based nanomotor, using a combined theoretical approach in the adiabatic and large-interaction regime.

Contribution

It introduces a novel theoretical framework combining slave-boson approximation with linear response to analyze strongly interacting quantum dots as motors.

Findings

Interactions cause a resonance shift.

Interactions increase quantum motor efficiency.

Additional ac-parameters emerge due to interactions.

Abstract

We study the relation between quantum pumping of charge and the work exchanged with the driving potentials in a strongly interacting ac-driven quantum dot. We work in the large-interaction limit and in the adiabatic pumping regime, and we develop a treatment that combines the time-dependent slave-boson approximation with linear response in the rate of change of the ac-potentials. We find that the time evolution of the system can be described in terms of equilibrium solutions at every time. We analyze the effect of the electronic interactions on the performance of the dot when operating as a quantum motor. The main two effects of the interactions are a shift of the resonance and an enhancement of the efficiency with respect to a non-interacting dot. This is due to the appearance of additional ac-parameters accounting for the interactions that increase the pumping of particles while decreasing the conductance.