Quantum Dynamics with BECs: Fluctuations, Phase Transitions and Hydrodynamic Analogies

About This Grant

Physical systems at nanoscopic scales or ultracold temperatures often exhibit pronounced quantum mechanical behavior. The laws of quantum mechanics are markedly different from classical mechanics, which opens up new possibilities for advanced applications in sensing, secure communication, computation and more. To harness this potential, fundamental studies are required that probe and characterize the quantum regime. To this end, the research team will employ an ultracold-atomic-gas platform as a well-controlled model system. Using laser-cooling and related techniques, a cloud of atoms will be cooled until a Bose-Einstein condensate (BEC) forms as a state of quantum mechanical matter. Additional specially tailored laser fields will be used to create a variety of quantum phases, and to study dynamics near critical points where phase transitions occur. Near these points small changes of system parameters can lead to strong changes in the properties of the system, making those points particularly promising for future sensing applications. The resulting data will provide important benchmarks for accompanying theoretical research. The experiments will be conducted at Washington State University, where they will play a key role in the education of students in the lab and in the classroom, contributing to the development of a workforce that is ready to meet the needs of the rapidly growing quantum industry. The research builds on extensive experience in the PI’s lab with spin-orbit coupled BECs. These systems consist of a BEC held in an optical trap, onto which additional Raman lasers are shone that couple different hyperfine states. An additional optical lattice is used to create state-independent couplings. The system is dynamically very rich, hosting a variety of quantum phases and phase transitions. A sequence of experiments will study quantum phase transitions induced by rapid quenches of system parameters. Topics of particular focus include Josephson physics, quantum fluctuations, chaos assisted tunneling, and Kibble-Zurek physics. A hydrodynamic approach based on large dark-bright soliton trains will also be studied as a complementary approach providing a new viewpoint on the underlying physics. The acquired data will contribute to the development of a comprehensive theoretical understanding of quantum dynamics, paving the way for future applications in quantum sensing or quantum information processing. 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.