Title: Temperature Interfaces in the Katz-Lebowitz-Spohn Driven Lattice Gas
Abstract: We explore the intriguing spatial patterns that emerge in a two-temperature Katz-Lebowitz-Spohn (KLS) model in two dimensions, a driven lattice gas with attractive nearest-neighbor interactions and periodic boundary conditions. The domain is split into two regions with hopping rates governed by different temperatures T > Tc and Tc, respectively, where Tc indicates the critical temperature for phase ordering, and with the temperature boundaries oriented either transverse or parallel to the drive. For a transverse temperature interface, the system behaves like the (totally) asymmetric exclusion process (T)ASEP in the hotter region, and experiences particle blockage in front of the boundary to the critical region. In analogy with TASEP systems containing "slow" bonds, transport in the high-temperature subsystem is impeded by the lower current in the cooler region, which tends to set the global stationary particle current value. We observe the density profiles in both high-and low-temperature subsystems to be strikingly similar to the well-characterized coexistence and maximal-current phases in (T)ASEP models with open boundary conditions, namely governed by hyperbolic / trigonometric tangent functions. If the lower temperature is set at Tc, we instead detect the corresponding critical power law density decay. For a parallel interface, we observe the critical region to act as an absorbing sink for particle transport. If one part of the system is held at temperature T