title: Observation of Half-Quantum Vortices in Topological Superfluid ^{3}He.
abstract: One of the most sought-after objects in topological quantum-matter systems is a vortex carrying half a quantum of circulation. They were originally predicted to exist in superfluid ^{3}He-A but have never been resolved there. Here we report an observation of half-quantum vortices (HQVs) in the polar phase of superfluid ^{3}He. The vortices are created with rotation or by the Kibble-Zurek mechanism and identified based on their nuclear magnetic resonance signature. This discovery provides a pathway for studies of unpaired Majorana modes bound to the HQV cores in the polar-distorted A phase.
authors.affiliation: Low Temperature Laboratory, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 AALTO, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Autti
authors.affiliation: P. L. Kapitza Institute for Physical Problems of RAS, 119334 Moscow, Russia.
authors.forename: V V
authors.initials: VV
authors.lastname: Dmitriev
authors.affiliation: Low Temperature Laboratory, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 AALTO, Finland.
authors.forename: J T
authors.initials: JT
authors.lastname: Mäkinen
authors.affiliation: P. L. Kapitza Institute for Physical Problems of RAS, 119334 Moscow, Russia.|Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia.
authors.forename: A A
authors.initials: AA
authors.lastname: Soldatov
authors.affiliation: Low Temperature Laboratory, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 AALTO, Finland.|Landau Institute for Theoretical Physics, 142432 Chernogolovka, Russia.
authors.forename: G E
authors.initials: GE
authors.lastname: Volovik
authors.affiliation: P. L. Kapitza Institute for Physical Problems of RAS, 119334 Moscow, Russia.
authors.forename: A N
authors.initials: AN
authors.lastname: Yudin
authors.affiliation: Low Temperature Laboratory, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 AALTO, Finland.
authors.forename: V V
authors.initials: VV
authors.lastname: Zavjalov
authors.affiliation: Low Temperature Laboratory, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 AALTO, Finland.
authors.forename: V B
authors.initials: VB
authors.lastname: Eltsov