Inverse currents in Coulomb-coupled quantum dots

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

Automated summary

The phenomenon of inverse current has been discovered in both classical and quantum systems, especially in Coulomb-coupled quantum dot system where the inverse current appears as Coulomb interaction increases. Despite the entropy reduction caused by the inverse current, it is balanced by the entropy increase caused by the forward current, ensuring that the total entropy increase of the system is always greater than zero.