V-3　Spin Dynamics in Frustrated Magnets—Spin Molecules Hidden in Spinel Oxides—

Abstract

The concept of frustration has driven the modern research fields of magnetism and strongly correlated electron systems. In frustrated magnets, even at a much lower temperature than the scale of magnetic bonding energy, a spin system does not form a normal static long-range order but forms a novel liquid-like state. The representative state is molecular spin excitation modes in spinel oxides, which refers to the picture of spin motions confined in a beautiful geometrical figure within 1 nm. We introduce molecular spin excitations from the discovery to recent results around our inelastic neutron scattering studies.