Early work on the dynamics of ensembles of tunneling magnetic
molecules established the main features of their quantum relaxation;
the role of inter-molecular dipolar interactions, the influence of
nuclear spins, and the way in which an external applied field
influences the tunneling of individual molecular spins. Some
questions still remain open - there is no proper theory of the
relaxation dynamics under fast sweeping of the external field, and
many interesting features of the experimental results remain
unexplained. At the same time there has been enormous progress in
synthesizing and exploring the properties of many different
molecules in the last decade.
However the frontier has now shifted to the understanding of the
coherent quantum dynamics of these systems, either as individual
molecules, or as interacting ensembles. Experiments must now examine
the resonance properties of these systems, looking for coherent Rabi
oscillations or, better still, spin echo results. Undoubtedly one of
the reasons for interest in this is the possibility that these
molecules might be good candidates for qubits in some quantum
information processing system. The main theoretical problem to
understand here is decoherence in the molecules spin dynamics,
caused by nuclear spins, phonons, and dipolar interactions; this
problem is very complex. Experiments are thus probing the coupled
dynamics of pairs of molecules, which is quite intricate - direct
probing of entanglement in their dynamics should soon be achieved in
such experiments.
This shift in emphasis has imposed new demands on the kinds of
molecules that are interesting. At the same time chemists have been
making a wide variety of new molecular magnets, no longer based
exclusively on transition metal ions but also incorporating rare
earths. These new systems will certainly open the door to new kinds
of experiment, requiring different theoretical perspectives.
This meeting will bring together chemists with experimental and
theoretical physicists interested in various aspects of these
remarkable systems, which have in the last few years suggested quite
new lines of research in quantum nanoscience.
