Cooling atoms to ultralow temperatures has produced a wealth of opportunities in
fundamental physics, precision metrology, and quantum science. The more recent …

1. INTRODUCTION Beams of atoms and molecules are stalwart tools for spectroscopy and
studies of collisional processes. 1− 4 The supersonic expansion technique can create cold …

Full control of molecular interactions, including reactive losses, would open new frontiers in
quantum science. We demonstrate extreme tunability of ultracold chemical reaction rates by …

Ultracold molecules offer unprecedented opportunities for the controlled interrogation of
molecular events, including chemical reactivity in the ultimate quantum regime. The …

The motion of neutral molecules in a beam can be manipulated and controlled with
inhomogeneous electric and magnetic fields. Static fields can be used to deflect or focus …

Molecular collisions in the quantum regime represent a new opportunity to explore chemical
reactions. Recently, atom-exchangereactions were observed in a trapped ultracold gas of …

Experiments have lagged theory in exploring chemical interactions at temperatures so low
that translational degrees of freedom can no longer be treated classically. The difficulty has …

The goal of the present article is to review the major developments that have led to the
current understanding of molecule–field interactions and experimental methods for …

The field of experimental positronium physics has advanced significantly in the last few
decades, with new areas of research driven by the development of techniques for trapping …

Collisions between cold polar molecules represent a fascinating research frontier but have
proven hard to probe experimentally. We report measurements of inelastic cross sections for …