Steven L. Johnson

TL;DR: These results resolve a long-standing issue about the population mechanism of quintet states in iron(II)-based complexes, which are identified as a simple 1MLCT→3 MLCT→5T cascade from the initially excited state.

TL;DR: Time-resolved x-ray diffraction with picosecond temporal resolution is used to observe scattering from impulsively generated coherent acoustic phonons in laser-excited InSb crystals and shows that the first step in the transition to a disordered state is the excitation of large amplitude, coherent atomic motion.

TL;DR: The results show that it is possible to directly manipulate atomic-scale magnetic structures with the electric field of light on a sub-picosecond time scale.

TL;DR: Time-resolved X-ray diffraction is applied to directly measure the changes in long-range order during ultrafast melting of the charge and orbitally ordered phase in a perovskite manganite to find the dynamics of the phase transformation can be well described using a single time-dependent 'order parameter' that depends exclusively on the electronic excitation.

TL;DR: The structural relaxation from the high spin to the low spin state was followed over the entire lifetime of the excited state and an Fe-N bond elongation of 0.2 A in the quintet state compared to the singlet ground state is delivered.