title: Frozen State and Spin Liquid Physics in Na_{4}Ir_{3}O_{8}: An NMR Study.
abstract: Na_{4}Ir_{3}O_{8} is a unique case of a hyperkagome 3D corner sharing triangular lattice that can be decorated with quantum spins. It has spurred a lot of theoretical interest as a spin liquid candidate. We present a comprehensive set of NMR data taken on both the ^{23}Na and ^{17}O sites. We show that disordered magnetic freezing of all Ir sites sets in below T_{f}~7 K, well below J=300 K, with a drastic slowing down of fluctuations to a static state revealed by our T_{1} measurements. Above typically 2T_{f}, physical properties are relevant to the spin liquid state induced by this exotic geometry. While the shift data show that the susceptibility levels off below 80 K, 1/T_{1} has little variation from 300 K to 2T_{f}. We discuss the implication of our results in the context of published experimental and theoretical work.
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud 11, UMR CNRS 8502, 91405 Orsay, France.
authors.forename: A C
authors.initials: AC
authors.lastname: Shockley
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud 11, UMR CNRS 8502, 91405 Orsay, France.
authors.forename: F
authors.initials: F
authors.lastname: Bert
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud 11, UMR CNRS 8502, 91405 Orsay, France.
authors.forename: J-C
authors.initials: JC
authors.lastname: Orain
authors.affiliation: Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Okamoto
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud 11, UMR CNRS 8502, 91405 Orsay, France.
authors.forename: P
authors.initials: P
authors.lastname: Mendels