Surface spin-flop and discommensuration transitions in antiferromagnets.
Cristian Micheletti
Abstract
We discuss the ground-state phase diagram of an infinite,
semi-infinite and finite chain of antiferromagnetically coupled spins
with uniaxial spin anisotropy under the influence of an external
magnetic field.
For the semi-infinite chain we show that surface spin-flop states
originate at a single multiphase point at a finite value of the spin
anisotropy. It is shown that the first-order boundaries between the
different spin-flop states terminate in critical points. We also
identify for the first time a second series of first-order transitions
in finite chains of even length. This enables us to clarify the
mechanism by which the surface spin-flop states evolve into the bulk
spin-flop state.
Elenco dei partecipanti al convegno di Bari.