Magnetic monopolies in spin ice
When: March 20, 2008 (Thu), 01:30PM to 02:30PM
Location: SCI 352
Note: Condensed Matter Theory Seminar
Speaker: Claudio Castelnovo, Univeristy of Oxford, UK
Electrically charged particles, such as the electron, are ubiquitous. By contrast, no elementary particles with a net magnetic charge have ever been observed, despite intensive and prolonged searches. We pursue an alternative strategy, namely that of realizing them not as elementary but rather as emergent particles, i.e., as manifestations of the correlations present in a strongly interacting many-body system. Here we show that magnetic monopoles do emerge in a class of exotic magnets known collectively as spin ice: the dipole moment of the underlying electronic degrees of freedom fractionalises into monopoles in a process that we term Dirac string condensation.