Iman Abdoli

I am a PhD student at the Leibniz-Institut für Polymerforschung, Dresden in the Institut Theorie der Polymere. My field of research is the study of out of equilibrium systems using statistical mechanics. I am especially interested in Lorentz forces in soft matter.


Research areas

Lorentz force in soft matter

Nondiffusive fluxes in Brownian systems

In the presence of Lorentz force due to an external magnetic field, the Fokker-Planck equation picks up a tensorial coefficient, which reflects the anisotropy of the particle's motion giving rise to diffusive fluxes and additional nondiffusive (or Lorentz) fluxes in the system. These nondiffusive fluxes are important for calculating noneuilibrium properties of the system.

Novel stationary state in Brownian systems

The equilibrium properties of Brownian systems subjected to Lorentz force, due to an external magnetic field, are unaffected by the applied magnetic field. We show that by stochastically resetting a Brownian particle, a nonequilibrium steady state can be created which preserves the hallmark features of dynamics under Lorentz force (see the left figure). We then consider a minimalistic example of spatially inhomogeneous magnetic field (see the right figure), which shows how additional Lorentz fluxes fundamentally alter the boundary conditions giving rise to a novel stationary state.

Multithermostat Brownian systems

We study the motion of a Brownian particle subjected to Lorentz force due to an external magnetic field. Each spatial degree of freedom of the particle is coupled to a different thermostat. The magnetic field results in correlations between different velocity components which persist in the stationary state. Using a first-principles approach we obtain the velocity autocorrelation tensor, thereby calculating the tensor that enters the Fokker-Planck equation for the probability density. In contrast to previous studies, even for an isotropic harmonic potential, a nontrivial steady-state density distribution exists which depends on both the sign and magnitude of the applied magnetic field. By breaking the symmetry using a spatially inhomogeneous magnetic field, we show that there exist fluxes in the system.

The density distribution in the system relaxing towards the equilibrium steady state.
The fluxes in the system relaxing towards the equilibrium steady state.

Asymmetric Exclusion Process

The asymmetric simple exclusion process (or ASEP) is a one-dimensional lattice with a row of L boxes. Each box can utmost carry one particle (i.e. exclusion). The particles jump stochastically from site to site, with a rate p, normalised to 1 in the figure, to the right and a rate q < 1 to the left (i.e. asymmetry). In the open ASEP, particles can enter (leave) the system at the first and the last boxes. In the figure, there is a particle current from the left reservoir to the right one.

An ASEP with open boundary conditions such that particles can enter the system from the left bounary with rate α and from the right boundary with rate δ. These particle can leave the system at sites 1 and L with rate γ and β, respectively.

Education

  • 2018-present

PhD Student in Physics at the Leibniz Institute for Polymer reseach Dresden, Germany

  • 2014-2016

Master of Science in Solid State Physics at Bu-Ali Sina Univesity of Hamedan, Iran

  • 2007-2013

Bachelor of Science in Atomic Physics at Bu-Ali Sina University of Hamedan, Iran

Publications

  1. I. Abdoli, H.D. Vuijk, J.U. Sommer, J.M. Brader, A. Sharma, Nondiffusive fluxes in a Brownian system with Lorentz force, Phys. Rev. E 101, 012120 (2020)

  2. I. Abdoli, H.D. Vuijk, R. Wittmann, J.U. Sommer, J.M. Brader, A. Sharma, Stationary state in Brownian systems with Lorentz force, Phys. Rev. Research 2, 023381 (2020)





Contact

Address

Institute Theory of Polymers,Leibniz Institute of Polymer Research,Kaitzer Strasse 4,01069 DresdenGermany