Probing nonequilibrium transport and density profiles in tilted interacting fermion chains with local reservoirs

Abstract

We investigate how local particle reservoirs can probe transport and density profiles in tilted spinless fermion chains with nearest-neighbor interactions. Using finite-chain Lindblad calculations with particle injection and extraction at opposite ends, we define a threshold-dependent transmission range from the stationary current as the chain length is varied. This range decreases with increasing tilt and follows the trends of the equilibrium density-crossover width in the parameter regimes studied. Interactions can enhance transmission by compensating field-induced energy costs, whereas strongly polarized configurations suppress transport. A third, weakly coupled extraction reservoir provides a complementary spatial probe: its current is exactly proportional to the local occupation in the presence of the probe, and the normalized current approaches the unperturbed nonequilibrium density as the probe coupling vanishes. We illustrate the detection of staggered density modulations and show that bulk densities can continue to relax after boundary currents have nearly stabilized. These protocols connect current measurements to spatial transmission and density structure in driven interacting chains.

22 pages, 13 figures