Abstract of Publication No. 406
Abstract:Quantum magnetism exhibits unique
collective features, bearing no classical analogies. The unconventional
magnetic excitations realised in S =1/2 copper insulators KCuCl3
and TlCuCl3 were investigated by inelastic neutron scattering.
We identify in TlCuCl3 a promising candidate for the
microscopic study of a quantum phase transition, driven by zero-point spin
fluctuations at the lowest temperature. Such
novel studies often remained precluded to neutron scattering due to the
lack of suitable samples. Nevertheless, they address some of the most
fundamental and debated issues of condensed matter physics.