Quantum Phases, Interactions and Topology of Dressed BECs

Washington State University, Pullman WA

Investigators

Abstract

When a gas of atoms is cooled to a temperature close to absolute zero, it exhibits unusual behavior described by the theory of quantum mechanics. According to this theory, atoms have both a particle-like and a wave-like nature at the same time, which gives rise to behaviors that do not seem intuitive based on ordinary experience in everyday life. This project consists of a line of research using tailored laser and radio-frequency fields to investigate inherently quantum mechanical phenomena including unusual states of matter, the role of interatomic interactions in precision measurement schemes, and a new paradigm for modelling general quantum systems using ultracold atoms. This project will promote the progress of science and technology by providing insight into intricate quantum mechanical effects in a well-controlled environment that involves quantum complexities while remaining simple enough to be amenable to the development of new mathematical descriptions. Since quantum mechanical behavior becomes dominant not only in the realm of ultracold temperatures but also in the realm of very small dimensions, the knowledge acquired through this project will also provide impetus for the development of next generation nanoelectronics devices, for precision measurement or for quantum information. This project uses dilute-gas Bose-Einstein condensates formed by cooling rubidium atoms to temperatures near zero Kelvin. The atoms in the condensate form a macroscopic quantum system that can be manipulated and probed in very flexible ways. The project consists of a series of steps: First, by employing a suitably tailored light field comprised of the superposition of a Raman coupling field and an optical lattice, the excitation spectrum of a supersolid-like state will be studied that the Principal Investigator has recently realized in the lab. Second, a set of precision measurements will investigate the role of interaction effects in Raman dressing schemes and radio-frequency coupling schemes within the context of atom interferometry. This will illuminate the importance of interactions for quantum analog simulations. A clear cut demonstration of these interaction effects will be provided in the context of a spin tensor-momentum coupling scheme that leads to a variety of novel quantum phases. Finally, a new paradigm for quantum analog simulation will be experimentally realized by exploiting the parameter space of coupled internal states. This method has the potential to realize topological monopoles, enhancing our insight into advanced quantum mechanical concepts. 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.