Cold atoms: A field enabled by light

International audienceBesides being a source of energy, light can also cool gases of atoms down to the lowest temperatures ever measured, where atomic motion almost stops. The research field of cold atoms has emerged as a multidisciplinary one, highly relevant, e.g., for precision measurements, quantum gases, simulations of many-body physics, and atom optics. In this focus article, we present the field as seen in 2015, and emphasise the fundamental role in its development that has been played by mastering light. Introduction Cold atom physics has become a mature field of research , but this maturity has been achieved relatively fast. Ideas about mechanical action of light have existed for a long time, and there were preliminary experiments in the late '60s and in the '70s involving cooling and trapping of atoms with light. However, the significant experimental developments gathered momentum in the mid '80s. There are many conceptual and technological ingredients involved in this research. However, one thing that runs through everything at every stage is light. Without the ability to control and detect light with high precision, the field of cold atoms would not exist. This article about cold atoms, inspired by the International Year of Light 2015, is therefore dedicated to light