SP Seminar @SISSA Via Bonomea 265 - Thursday 21 November at 10:30 am - Uwe TAUBER

[CM Section]

Kindly note UNUSUAL DAY and TIME

Joint ICTP/SISSA Statistical Physics Seminar

Thursday 21 November at 10:30 a.m.
venue: SISSA, Via Bonomea 265

Speaker: Uwe TAUBER
Virginia Tech, U.S.A.

Title: Temperature Interfaces in the Katz-lebowitz-Spohn
Driven Lattice Gas

Abstract:
We explore the intriguing spatial patterns that emerge in a 
two-dimensional spatially inhomogeneous Katz-Lebowitz-Spohn (KLS) driven 
lattice gas with attractive nearest-neighbor interactions. The domain is 
split into two regions with hopping rates governed by different 
temperatures T > T_c and T_c, respectively, where T_c indicates the 
critical temperature for phase ordering, and with the temperature 
boundaries oriented perpendicular to the drive. In the hotter region, 
the system behaves like the (totally) asymmetric exclusion processes 
(TASEP), and experiences particle blockage in front of the interface to 
the critical region. To explain this particle density accumulation near 
the interface, we have measured the steady-state current in the KLS 
model at T > T_c and found it to decay as 1/T. 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. This blockage 
is induced by the extended particle clusters, growing logarithmically 
with system size, in the critical region. We observe the density 
profiles in both high-and low-temperature subsystems to be similar to 
the well-characterized coexistence and maximal-current phases in (T)ASEP 
models with open boundary conditions, which are respectively governed by 
hyperbolic and trigonometric tangent functions. Yet if the lower 
temperature is set to T_c, we detect marked fluctuation corrections to 
the mean-field density profiles, e.g., the corresponding critical KLS 
power law density decay near the interfaces into the cooler region. If 
the temperature interface is aligened parallel to the drive, we observe 
the cooler region to act as an absorbing sink for particle transport, 
with blockages emerging at the subsystem boundaries.