arXiv:1706.07744 · Physical review. B./Physical review. B
Boundary-driven Heisenberg chain in the long-range interacting regime: Robustness against far-from-equilibrium effects
Leon Droenner, Alexander Carmele
Abstract
We investigate the Heisenberg $XXZ$ chain with long-range interactions in the $Z$ dimension. By applying two magnetic boundary reservoirs, we drive the system out of equilibrium and induce a nonzero steady-state current. The long-range coupled chain shows nearly ballistic transport and linear response for all potential differences of the external reservoirs. In contrast, the common isotropic nearest-neighbor coupling shows negative differential conductivity and a transition from diffusive to subdiffusive transport for a far-from-equilibrium driving. Adding disorder, the change in the transport for nearest-neighbor coupling is therefore highly dependent on the driving. We find for the disordered long-range coupled $XXZ$ chain, any change in the transport behavior is independent of the potential difference and the coupling strengths of the external reservoirs.