Within a classical approximation, they have macroscopically many ground states which are unrelated by symmetry, and at low temperatures they show both strong correlations and large fluctuations. Nearest neighbour antiferromagnets on the pyrochlore lattice have become standard examples of such systems. The chromium spinels ZnCr2O4 and MgCr2O4are interesting for being approximate realisations of the Heisenberg pyrochlore antiferromagnet, and provide a contrast to the Ising spin-ice materials. In this talk I will review current theoretical and experimental understanding of the behaviour of geometrically frustrated magnets at low temperature and describe efforts to understand neutron scattering from these chromium spinels.
|Start date and time|| Tuesday 19 February 2013, 13:30 |
|End|| Tuesday 19 February 2013, 14:30 |