Laser-Cooled Antimatter
The photon, the quantum excitation of the electromagnetic field, is massless but carries momentum. Hence a photon can exert a force on an object upon collision. The application of such a force to slow the motion of atoms or ions, a technique known as laser cooling, was first demonstrated 40 years ago, and it literally revolutionized the field of atomic physics ever since. However, the technique had never been applied to antimatter – until recently.
A primary goal of antihydrogen studies at CERN’s Antiproton Decelerator facility is to test fundamental symmetries between matter and antimatter via precise comparisons of antihydrogen with its well-studied matter counterpart, hydrogen. Since the initial production of cold antihydrogen atoms in 2002, significant progress has been made. In this talk, following a brief overview of antimatter studies at CERN, I will describe our recent achievement on laser cooling of antihydrogen atoms. Our new ability to manipulate the motion of antimatter atoms will have significant impact in ongoing experiments on spectroscopy and gravitational studies of antihydrogen. Furthermore, it could provide opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules.