Measurement of Magnetization Dynamics in Single-Molecule Magnets Induced   by Pulsed Millimeter-Wave Radiation
  We describe an experiment aimed at measuring the spin dynamics of the Fe8 single-molecule magnet in the presence of pulsed microwave radiation. In earlier work, heating was observed after a 0.2-ms pulse of intense radiation, indicating that the spin system and the lattice were out of thermal equilibrium at millisecond time scale [Bal et al., Europhys. Lett. 71, 110 (2005)]. In the current work, an inductive pick-up loop is used to probe the photon-induced magnetization dynamics between only two levels of the spin system at much shorter time scales (from ns to us). The relaxation time for the magnetization, induced by a pulse of radiation, is found to be on the order of 10 us. 
M. Bal, Jonathan R. Friedman, M. T. Tuominen, E. M. Rumberger, and D.   N. Hendrickson