This experimental research program focuses on the investigation of atomic Bose-Einstein condensates (BEC) with internal spin degrees of freedom. These so-called spinor condensates offer a new form of coherent matter (quantum gas) with complex internal quantum structures that depend sensitively on the fine details of the inter-atomic interactions. This research will build upon the PIs recent investigations of spinor condensates created directly in all-optical traps in which the group studied the nature of the spinor ground state of the system and dynamical evolution of excited spin states. The broader impact of the program involves education as well as applications to sensors and clocks.
This research investigated many-body quantum behavior in spinor condensates focusing on generating and studying quantum-correlated spin states including squeezed and entangled states. These studies provided insight into fundamental principles of many-particle quantum mechanics that are important to many areas of physics. Additionally, squeezed and entangled states have a wide range of applications in quantum metrology, foundational studies of quantum mechanics, quantum information and quantum simulations. Spin-1 atomic Bose-Einstein condensates also provide a compelling system to investigate nematic or quadrupolar ordering of spins, which is an example of an exotic type of magnetic order resulting from collective behavior of quantum spins. In this grant period, we explored these fascinating quantum spin states and demonstrated spin-nematic squeezed states created in a spin-1 condensate quenched through a nematic-ferromagnetic quantum phase transition. Our research shows that simple evolution of a spin-1 condensate is a robust way to generate spin-nematic squeezed states with large amounts of squeezing. These states, together with the tools we have demonstrated for their characterization, can be used for quantum metrology of magnetic fields and for atomic clocks. Additionally, these experiments will provide new paths to explore the fascinating intersections of correlations, entanglement and quantum phase transitions in an exotic quantum spin system. More broadly, work in ultra-cold atomic physics is a new frontier of research in AMO physics with important potential impact in many areas of science and technology. Ultra-cold atoms and molecules are important tools in studies of low-energy collisions, quantum degenerate gases (including Bose-Einstein condensates and degenerate Fermi gases) and precision measurements of fundamental constants and symmetries. Technological applications of these systems include precision sensors for navigation and magnetometry, atomic clocks and emerging quantum technologies including quantum information and communication. Ultra-cold atoms also provide new tools to investigate important problems in condensed matter physics including exotic magnetic order thought to arise in a wide variety of frustrated magnetic materials and unconventional superconductors.
