Quantum control of molecular collisions at 1 kelvin

Abstract

Tracking collisions in just one beam Much of what we know about how quantum mechanics dictates chemical dynamics comes from half a century of studying controlled collisions between crossed pairs of molecular beams. Perreault et al. now show that even finer detail emerges in a study of hydrogen-deuterium (HD) collisions with D 2 in a single beam. The experimental setup lowers the collision temperature to ∼1 K, allowing precise control over the rotational energy and relative alignment of the colliding partners. Scattering events in which HD loses rotational energy occurred three times as readily if the HD was aligned perpendicular rather than parallel to the beam-propagation axis. Science , this issue p. 356