1,245 research outputs found
Nonequilibrium field-induced phase separation in single-file diffusion
Using an analytically tractable lattice model for reaction-diffusion
processes of hard-core particles we demonstrate that under nonequilibrium
conditions phase coexistence may arise even if the system is effectively
one-dimensional as e.g. in the channel system of some zeolites or in artificial
optical lattices. In our model involving two species of particles a
steady-state particle current is maintained by a density gradient between the
channel boundaries and by the influence of an external driving force. This
leads to the development of a fluctuating but always microscopically sharp
interface between two domains of different densities which are fixed by the
boundary chemical potentials. The internal structure of the interface becomes
very simple for strong driving force. We calculate the drift velocity and
diffusion coefficient of the interface in terms of the microscopic model
parameters.Comment: 38 pages, 2 figure
Shocks in the asymmetric exclusion process with internal degree of freedom
We determine all families of Markovian three-states lattice gases with pair
interaction and a single local conservation law. One such family of models is
an asymmetric exclusion process where particles exist in two different
nonconserved states. We derive conditions on the transition rates between the
two states such that the shock has a particularly simple structure with minimal
intrinsic shock width and random walk dynamics. We calculate the drift velocity
and diffusion coefficient of the shock.Comment: 26 pages, 1 figur
A Deterministic Polynomial--Time Algorithm for Constructing a Multicast Coding Scheme for Linear Deterministic Relay Networks
We propose a new way to construct a multicast coding scheme for linear
deterministic relay networks. Our construction can be regarded as a
generalization of the well-known multicast network coding scheme of Jaggi et
al. to linear deterministic relay networks and is based on the notion of flow
for a unicast session that was introduced by the authors in earlier work. We
present randomized and deterministic polynomial--time versions of our algorithm
and show that for a network with destinations, our deterministic algorithm
can achieve the capacity in uses of the
network.Comment: 12 pages, 2 figures, submitted to CISS 201
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