Quantum gas. Illustration of the record-breaking ultracold quantum gas of potassium-rubidium molecules produced by researchers at the Joint Institute for Laboratory Astrophysics (JILA). This gas can be used to create quantum crystals in which spin properties can migrate between molecules. Such quantum crystals could lead to the development of new materials. JILA is jointly operated by the University of Colorado Boulder and the National Institute of Standards and Technology (NIST). Image published in 2019.