Короткий опис(реферат):
Flexible ferromagnetic rings are spin-chain magnets, in which the magnetic and mechanical subsystems
are coupled. The coupling is achieved through the tangentially oriented anisotropy axis. The possibility to
operate the mechanics of the nanomagnets by controlling their magnetization is an important issue for the
nanorobotics applications. A minimal model for the deformable curved anisotropic Heisenberg ferromagnetic
wire is proposed. An equilibrium phase diagram is constructed for the closed loop geometry: (i) A vortex state
with vanishing total magnetic moment is typical for relatively large systems; in this case, the wire has the form
of a regular circle. (ii) A topologically trivial onion state with the planar magnetization distribution is realized in
small enough systems; magnetic loop is elliptically deformed. By varying geometrical and elastic parameters, a
phase transition between the vortex and onion states takes place. The detailed analytical description of the phase
diagram is well confirmed by numerical simulations.
