Inverse currents in Coulomb-coupled quantum dots

TL;DR

This paper demonstrates the existence of inverse current phenomena in quantum Coulomb-coupled quantum dots, showing that current can flow opposite to applied forces without violating thermodynamic laws.

Contribution

It reveals the presence of inverse currents in quantum systems, extending previous classical findings and analyzing their thermodynamic consistency.

Findings

Inverse current appears with increased Coulomb interaction.

Inverse current does not violate the second law of thermodynamics.

Total entropy of the system always increases.

Abstract

The inverse current, i.e., induced current is opposite to applied force, has recentlybeen found in a classical one-dimensional interacting Hamiltonian system [Phys. Rev.Lett. 124, 110607 (2020)]. In this paper, we show that inverse current also exists in quantum system. Based on Coulomb-coupled quantum dots system, we find that inverse current will appear when Coulomb interaction increases. This does not violate the second law of thermodynamics, since entropy reduction caused by inverse current is compensated by entropy increase caused by forward current, which ensure that total entropy increase of the system is always greater than zero.