Dynamical Laser Cooling of Ultranarrow Linewidth Atoms and Molecules

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

This theoretical research project explores a new and exciting idea where lasers are used to cool atoms and molecules to temperatures more than a million times colder than deep space. This innovative technique, dubbed SWAP cooling, employs extremely coherent lasers whose pure color is periodically modulated. Starting first as an accidental experimental discovery in the laboratory, this new technique promises to push back the frontier of what can be achieved in manipulating and controlling quantum gases, and to thereby have a broad range of potential applications in science and technology. This is not the first laser-cooling proposal; indeed the idea for using lasers to control and cool atomic gases has been explored extensively over the past two or three decades, and has led to the development of many methods that are used every day in atomic physics laboratories. However, this new approach has the potential to massively expand the range of atoms and molecules that can be considered for quantum science and quantum computation applications, and offers to improve state-of-the-art atomic clocks (used in such systems as GPS satellites for navigation). The novel idea is based on the premise that the extreme coherence offered by systems that have two valence electrons (group-II elements and other similar atomic and molecular systems) offers a new and exciting frontier for laser sciences. In these systems, the presence of extremely weak dipole transitions causes the implementation of traditional laser-cooling approaches to be difficult due in part to the demanding stability requirements for the laser frequencies. The new idea here is that near-resonant laser fields can be used whose intensity or frequency may be modulated in time. This may amplify the effects of strong coherent forces while simultaneously reducing the role of dissipative and spontaneous scattering of photons that would otherwise increase the realizable temperatures. The aim is to achieve, say, a ten-fold improvement in frequency standards that translates directly into potential major improvements in current technologies, ranging from improved metrology, to advanced communication, to the next generation of precision devices for navigation and positioning systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.