Speaker
Dominik Lips
(Universität Osnabrück, Germany)
Description
We present a model of a Brownian asymmetric simple exclusion process (BASEP) with underdamped Brownian Dynamics,
which is an extension on the well-known asymmetric simple exclusion process (ASEP)
defined on a discrete lattice. In the BASEP, particles of size $\sigma$ with hardcore interaction
are driven by a
constant drag force through a one-dimensional cosine potential with period $\lambda$. The amplitude
of the cosine potential is much larger than $k_{\rm\scriptscriptstyle B} T$,
leading to an effective hopping motion of particles
between potential wells. Under periodic boundary conditions, the system reaches a non-equilibrium steady-state (NESS) with a constant particle current. In general, the character of these NESS is strikingly different from the one in the ASEP. Compared to the particle current in a system of
non-interacting particles, we observe an enhancement for small $\sigma/\lambda$ ratios, caused by a barrier reduction
effect arising from multi-occupation of potential wells. Larger ratios lead to a suppression of the current because
of strong blocking effects. Surprisingly,
an exchange-symmetry effect leads to a current-density relation identical to that of non-interacting particles for the
commensurable length $\sigma=\lambda$. A current-density relation similar to the ASEP is obtained only for a
limited parameter regime. The rich behavior of the current-density relation is reflected in
non-equilibrium phase-diagrams for open-systems, which can exhibit up to five phases. The topology
of these phase diagrams changes with varying $\sigma/\lambda$ ratio. We furthermore discuss transition times and splitting probabilities for a tagged particle in the BASEP. These quantities exhibit a remarkable asymmetry, which we relate to the collective particle motion in the NESS.
Primary author
Dominik Lips
(Universität Osnabrück, Germany)
Co-authors
Dr
Artem Ryabov
(Charles University)
Prof.
Philipp Maass
(Universität Osnabrück, Germany)
