Supersymmetry of the magnetic vortex

The N=2 supersymmetry of the Pauli Hamiltonian in any static magnetic field in the plane combines, for the magnetic vortex, with Jackiw's bosonic $o(2)\times o(2,1)$ symmetry, into an $o(2)\times osp(1/2)$ dynamical supersymmetry.Comment: 4 pages. Originally Tours Preprint no 60/93 (1993). Unpublishe

Chiral fermions as classical massless spinning particles

Semiclassical chiral fermion models with Berry term are studied in a symplectic framework. In the free case, the system can be obtained from Souriau's model for a relativistic massless spinning particle by "enslaving" the spin. The Berry term is identified with the classical spin two-form of the latter model. The Souriau model carries a natural Poincar\'e symmetry that we highlight, but spin enslavement breaks the boost symmetry. However the relation between the models allows us to derive a Poincare symmetry of unconventional form for chiral fermions. Then we couple our system to an external electromagnetic field. For gyromagnetic ratio $g=0$ we get curious superluminal Hall-type motions; for $g=2$ and in a pure constant magnetic field in particular, we find instead spiraling motions.Comment: Substantially revised and extended version. 31 pages, 5 figures. Details clarified and references added. To be published in PR

Anyons with anomalous gyromagnetic ratio & the Hall effect

Letting the mass depend on the spin-field coupling as $M^2=m^2-(eg/2c^2)F_{\alpha\beta}S^{\alpha\beta}$, we propose a new set of relativistic planar equations of motion for spinning anyons. Our model can accommodate any gyromagnetic ratio $g$ and provides us with a novel version of the Bargmann-Michel-Telegdi equations in 2+1 dimensions. The system becomes singular when the field takes a critical value, and, for $g\neq2$, the only allowed motions are those which satisfy the Hall law. For each $g\neq2,0$ a secondary Hall effect arises also for another critical value of the field. The non-relativistic limit of our equations yields new models which generalize our previous ``exotic'' model, associated with the two-fold central extension of the planar Galilei group.Comment: The affiliation of the first author's Institution is presented in detail. LaTeX, 12 pages no figures. To appear in Phys. Lett.