Abstract:

Geometrically frustrated magnets are a rich playground for studying unusual ground states. Recent experimental results on the behavior of interacting spins on the kagome lattice will be discussed.  The kagome lattice, composed of corner-sharing triangles, is one of the most highly frustrated lattices in two-dimensions.  In a S=5/2 kagome system (iron jarosite), our neutron scattering measurements reveal a novel zero energy mode in the ordered state and diverging 2D spin correlations associated with the phase transition.  In a S=1/2 kagome antiferromagnet (ZnCu3(OH)6Cl2), thermodynamic and neutron measurements show evidence for an unusual quantum spin liquid state as the ground state