title: Short-range correlations in the magnetic ground state of Na₄Ir₃O₈.
abstract: The magnetic ground state of the J(eff)=1/2 hyperkagome lattice in Na₄Ir₃O₈ is explored via combined bulk magnetization, muon spin relaxation, and neutron scattering measurements. A short-range, frozen state comprised of quasistatic moments develops below a characteristic temperature of T(F)=6  K, revealing an inhomogeneous distribution of spins occupying the entirety of the sample volume. Quasistatic, short-range spin correlations persist until at least 20 mK and differ substantially from the nominally dynamic response of a quantum spin liquid. Our data demonstrate that an inhomogeneous magnetic ground state arises in Na₄Ir₃O₈ driven either by disorder inherent to the creation of the hyperkagome lattice itself or stabilized via quantum fluctuations.
authors.affiliation: Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Dally
authors.affiliation: Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Hogan
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
authors.forename: Alex
authors.initials: A
authors.lastname: Amato
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
authors.forename: Hubertus
authors.initials: H
authors.lastname: Luetkens
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
authors.forename: Chris
authors.initials: C
authors.lastname: Baines
authors.affiliation: NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: Jose
authors.initials: J
authors.lastname: Rodriguez-Rivera
authors.affiliation: Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Graf
authors.affiliation: Department of Materials, University of California, Santa Barbara, California 93106, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Wilson