At low temperatures wavelike properties of atoms and molecules start dominating reaction dynamics. Classically forbidden phenomena such as tunneling through potential barriers becomes the dominant reaction mechanism.
We have been the first to observe a sharp increase in the reaction rate because of quantum effects at temperatures reaching 0.01K.
In order to achieve this goal we had to develop a completely new approach to experimental cold chemistry.
We merge two cold supersonic beams using high magnetic fields. We can tune the reaction temperature from room temperature down to 0.01 K. This is almost 3 orders of magnitude lower in energy as compared to other molecular beam based methods.
Classical Reaction Regime - the chance for reactive interaction is limited to a single collision.
Quantum Reaction Regime - colliding particles tunnel through a potential barrier to become trapped in an orbiting motion. The probability for a chemical interaction is higher due to much longer collision time.
Published in Science 12 October 2012: A. B. Henson, S. Gersten, Y. Shagam, J. Narevicius, E. Narevicius, "Observation of Resonances in Penning Ionization Reactions at Sub-Kelvin Temperatures in Merged Beams", Science 338, 234 (2012) [DOI: 10.1126/science.1229141]