  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.
