Atomic and Molecular Physics(DAMP)
Physique atomique et moléculaire (DPAM)
Evgeny A. SHAPIRO
National Research Council
Arbitrary shaping of molecular wavepackets by AC Stark shifts
From a wavepacket perspective, quantum dynamics are viewed as a flow of probability and phase - in contrast with a few-level dynamics. Trying to control such processes, we have to think in terms of applying coordinate-dependent potentials rather than in terms of level-by-level addressability.
I shall describe control of quantum wavepackets using the combination of coordinate-dependent AC Stark shifts induced by short laser pulses (phase kicks) and free evolution. This approach resembles shaping wavepackets of light in optics. Like spatial light modulators in optics, the tools used allow arbitrary shaping of molecular wavepackets via interference of effective eigenstates of the so-called revival-scale evolution. The number of such eigenstates is determined by the accuracy of control we are interested in.
Numerical and experimental examples show how this technique allows one to control molecular alignment and orientation.
Next, I shall discuss relation of the wavepacket control to quantum information processing. It will be shown how several quantum bits can be encoded in the shape of a single wavepacket, and how the control can be implemented as a quantum computation.