title: Spatially Resolved Detection of a Spin-Entanglement Wave in a Bose-Hubbard Chain.
abstract: Entanglement is an essential property of quantum many-body systems. However, its local detection is challenging and was so far limited to spin degrees of freedom in ion chains. Here we measure entanglement between the spins of atoms located on two lattice sites in a one-dimensional Bose-Hubbard chain which features both local spin- and particle-number fluctuations. Starting with an initially localized spin impurity, we observe an outwards propagating entanglement wave and show quantitatively how entanglement in the spin sector rapidly decreases with increasing particle-number fluctuations in the chain.
authors.affiliation: Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.|RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fukuhara
authors.affiliation: Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Hild
authors.affiliation: Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Zeiher
authors.affiliation: Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Schauß
authors.affiliation: Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.|Ludwig-Maximilians-Universität, Fakultät für Physik, 80799 München, Germany.
authors.forename: Immanuel
authors.initials: I
authors.lastname: Bloch
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Manuel
authors.initials: M
authors.lastname: Endres
authors.affiliation: Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Gross