Liu Lab






Our research group at OSU has a sodium spinor Bose-Einstein condensate (BEC) lab and a rubidium BEC lab. Atomic BECs are ultracold quantum gases, which are so cold that all the atoms collapse into the same quantum state, becoming essentially indistinguishable from one another. Possessing an additional spin degree of freedom, spinor BECs constitute a fascinating collective quantum system offering an unprecedented degree of control over such parameters as spin, temperature, and the dimensionality of the system.


1. Sodium BEC lab


Research topics: utilize sodium spinor BECs in optical lattices as quantum simulators for condensed matter models, and develop quantum-enhanced precise magnetic field sensors.



Our sodium BEC lab has confined 100,000 ultracold spin-zero, spin-up, and spin-down atoms into cubic optical lattices. (Credit: Oklahoma State University)


Recent research highlights: our sodium BEC lab has made the first experimental observations of few-body non-equilibrium spin dynamics in an ultracold spinor BEC confined by cubic optical lattices. This research, published in the journal Physical Review Letters (PRL), offers a crucial bridge between the well-studied realms of two-body and many-body interactions. Understanding the transition between these realms is not only important fundamentally but also vital for future applications like quantum information science. We have experimentally demonstrated that lattice-confined spinor BECs provide a perfect platform to understand this complicated transition. Our experiments have been performed in a quantum quench scenario, in which we drive a BEC out of equilibrium by rapidly changing one experimental parameter. We have observed non-equilibrium dynamics consisting of spin-mixing oscillations at multiple frequencies after distinct quantum quench sequences. By identifying oscillation signatures of up to six atoms in a lattice site, we have confirmed that the observed dynamics can reveal atom number distributions of an inhomogeneous system and enable precise measurements of two important parameters determining the spinor physics.


2. Rubidium BEC lab


Research topics: quantum walks and topological phases.


Quantum to Classical Walk Transitions Tuned by Spontaneous Emissions, Physical Review Research 3, 043062 (2021)




We gratefully acknowledge financial support of our research from: