Ground State of the Quantum Spin Ice Yb2Ti2O7

Abstract

<p>We report low temperature specific heat and positive muon spin rotation measurements of both polycrystal and single crystal Yb2Ti2O7. Our zero field (ZF) measurements show little spin relaxation temperature dependence in the polycrystal Yb2Ti2O7, contrast to previously reported results. We observe no collinear ferromagnetic order, rather a hidden order ground state where spin fluctuations remain dynamic down to 16 mK. Single crystal Yb2Ti2O7 zero field measurements with the crystallographic [111] direction parallel to the initial muon polarization show small but measurable temperature dependence. In addition, our transverse field measurements show the spin susceptibility undergoes a distinct change at temperatures corresponding to the magnetic transition measured in the specific heat.</p>