Nondiffusive fluxes in a Brownian system with Lorentz force

Abdoli, Iman; Vuijk, H. D.; Sommer, J. U.; Brader, Joseph M.; Sharma, Abhinav

doi:10.1103/PhysRevE.101.012120

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Journal article

Nondiffusive fluxes in a Brownian system with Lorentz force

Abdoli, Iman Leibniz-Institut für Polymerforschung Dresden, Institut Theorie der Polymere, Dresden, Germany
Vuijk, H. D. Leibniz-Institut für Polymerforschung Dresden, Institut Theorie der Polymere, Dresden, Germany
Sommer, J. U. Leibniz-Institut für Polymerforschung Dresden, Institut Theorie der Polymere, Dresden, Germany - Technische Universität Dresden, Institut für Theoretische Physik, Dresden, Germany
Brader, Joseph M. Department de Physique, Université de Fribourg, Switzerland
Sharma, Abhinav Leibniz-Institut für Polymerforschung Dresden, Institut Theorie der Polymere, Dresden, Germany - Technische Universität Dresden, Institut für Theoretische Physik, Dresden, Germany

14.01.2020

Published in:

Physical Review E. - 2020, vol. 101, no. 1, p. 012120

English The Fokker-Planck equation provides a complete statistical description of a particle undergoing random motion in a solvent. 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. This tensor, however, cannot be interpreted as a diffusion tensor; there are antisymmetric terms which give rise to fluxes perpendicular to the density gradients. Here, we show that for an inhomogeneous magnetic field these nondiffusive fluxes have finite divergence and therefore affect the density evolution of the system. Only in the special cases of a uniform magnetic field or carefully chosen initial condition with the same full rotational symmetry as the magnetic field can these fluxes be ignored in the density evolution.

Faculty

Faculté des sciences et de médecine

Department

Département de Physique

Language