Front-end of an attosecond beamline: sub-5-fs pulses, characterized by an ultrabroad spectrum, are injected in a high-order harmonic generation chamber. [Maurizio Contran]
The laws of quantum mechanics dictate the relevant timescales of the microscale processes of chemistry. A single molecule, for example, can rotate and vibrate. Using quantum terminology, we can say that molecular rotations and vibrations relate to the generation of a coherent superposition of rotational and vibrational states—with rotations and vibrations evolving on picosecond and femtosecond timescales, respectively, depending on the energy difference between the states in the coherent superposition.