Pumping angular momentum by driven chaotic scattering

TL;DR

This paper investigates how a magnetic dipole in a modulated magnetic field exhibits chaotic scattering, leading to directed transport of angular momentum and mass, with potential for angular-momentum separation without mass flow.

Contribution

It demonstrates that broken symmetries in a chaotic scattering system can produce directed angular momentum transport and angular-momentum separation without mass transfer.

Findings

Chaotic scattering occurs in the model over large parameter regions.

Directed transport of angular momentum and mass is achieved when symmetries are broken.

Angular-momentum separation can occur without accompanying mass transport.

Abstract

Chaotic scattering with an internal degree of freedom and the possibility to generate directed transport of angular momentum is studied in a specific model, a magnetic dipole moving in a periodically modulated magnetic field confined to a compact region in space. We show that this system is an irregular scatterer in large parts of its parameter space. If in addition all spatio-temporal symmetries are broken, directed transport of mass as well as angular momentum occurs. The sensitive parameter dependence of the corresponding currents includes frequent sign reversals. Zeros of either quantity entail the exclusive occurrence of the other and thus give rise in particular to angular-momentum separation without mass transport as a classical analogue of spin-polarized currents.