"Title: Dynamics of Monopoles in Spin Ice

First, I will give an introduction to spin ice and magnetic monopoles.
Spin ices are frustrated ferromagnets which are recognized as a class
of magnets exhibiting unusual behavior such as residual entropy. In
spin ice, dipolar interaction dominates the nearest neighbor
interaction. Thus the spin configuration at low temperature consists
of two of the four spins in a tetrahedron pointing inwards, and the
others outwards (2-in, 2-out state). The 2-in, 2-out constraint is
called the ice rule. Violating the ice rules by flipping a spin out of
a ground state configuration, leads to a pair of pointlike defects in
the tetrahedra the spin
belongs to. These two defects are deconfined: they can be separated to
an arbitrarily large distance at a finite cost
in energy. We study the diffusion annihilation process which occurs
when spin ice in a [111] magnetic field is quenched from
a fully magnetized phase deep into the spin ice regime, where the
excitations - magnetic monopoles - are sparse."

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Joel Yuen-Zhou

PhD candidate in Chemical Physics

Harvard University CCB,

12 Oxford St. Mailbox 107,

Cambridge, MA, USA.