NCTS (South)


DATE2019-05-06

TIME12:10

PLACER49223, Second Physics Building , NCKU

FIELDQuantum Information Science

SPEAKER Prof. Yu-Ju Lin(林育如) - 中央研究院 原子與分子科學研究所

TITLELight-induced azimuthal gauge potentials and spin-orbital-angular-momentum coupling in atomic Bose-Einstein condensates

ABSTRACTWe demonstrate coupling between the atomic spin and orbital-angular-momentum (OAM) of the atom’s center-of-mass motion in a Bose-Einstein condensate (BEC), referred to as “spin-orbital-angular-momentum coupling”. This is achieved by using two co-propagating Raman-dressing beams to couple the atoms in the hyperfine spin F=1 manifold while transferring orbital-angular-momentum (OAM) to the atoms’ center-of-mass. One of the Raman beam is a Laguerre-Gaussian (LG) beam carrying OAM of light. In this system, we create synthetic azimuthal gauge potentials which act as effective rotations. We exploit the azimuthal gauge potential to demonstrate the Hess-Fairbank effect, the analogue of Meissner effect in superconductors. Our demonstration serves as a paradigm to create topological excitations by tailoring atom-light interactions. Further, the gauge field in the stationary Hamiltonian opens a path to investigating rotation properties of atomic superfluids under thermal equilibrium.