title: Collisional Dynamics of Half-Quantum Vortices in a Spinor Bose-Einstein Condensate.
abstract: We present an experimental study on the interaction and dynamics of half-quantum vortices (HQVs) in an antiferromagnetic spinor Bose-Einstein condensate. By exploiting the orbit motion of a vortex dipole in a trapped condensate, we perform a collision experiment of two HQV pairs, and observe that the scattering motions of the HQVs is consistent with the short-range vortex interaction that arises from nonsingular magnetized vortex cores. We also investigate the relaxation dynamics of turbulent condensates containing many HQVs, and demonstrate that spin wave excitations are generated by the collisional motions of the HQVs. The short-range vortex interaction and the HQV-magnon coupling represent two characteristics of the HQV dynamics in the spinor superfluid.
authors.affiliation: Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Korea.
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Seo
authors.affiliation: Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Korea.|Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Kwon
authors.affiliation: Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Korea.|Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea.
authors.forename: Seji
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Korea.|Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Shin