title: Topological aspects in spinor Bose-Einstein condensates.
abstract: This article overviews topological excitations in spinor Bose-Einstein condensates of dilute atomic gases. Various types of line defects, point defects and skyrmions are discussed. A brief review of homotopy theory is presented for use in the classification of possible topological excitations in individual quantum phases. Some recent experiments are also reviewed.
authors.affiliation: Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Ueda